The UK supreme court has ruled that the terms “woman” and “sex” in the Equality Act refer to a biological woman and biological sex, in a victory for gender-critical campaigners.

Five judges from the UK supreme court ruled unanimously that the legal definition of a woman in the Equality Act 2010 did not include transgender women who hold gender recognition certificates (GRCs).

In a significant defeat for the Scottish government, the court decision will mean that transgender women can no longer sit on public boards in places set aside for women.

It could have far wider ramifications by leading to much greater restrictions on the rights of transgender women to use services and spaces reserved for women, and prompt calls for the UK’s laws on gender recognition to be rewritten.

The UK government said the ruling “brings clarity and confidence” for women and those who run hospitals, sports clubs and women’s refuges.

A spokesperson said: “We have always supported the protection of single sex spaces based on biological sex. Single-sex spaces are protected in law and will always be protected by this government.”

John Swinney, Scotland’s first minister, posted on social media: “The Scottish government accepts today’s supreme court judgment. The ruling gives clarity between two relevant pieces of legislation passed at Westminster. We will now engage on the implications of the ruling. Protecting the rights of all will underpin our actions.”

Lord Hodge told the court the Equality Act (EA) was very clear that its provisions dealt with biological sex at birth, and not with a person’s acquired gender, regardless of whether they held a gender recognition certificate.

That affected policymaking on gender in sports and the armed services, hospitals, as well as women-only charities, and access to changing rooms and women-only spaces, he said.

In a verbal summary of the decision, he said: “Interpreting sex as certificated sex would cut across the definitions of man and woman in the EA and thus the protected characteristic of sex in an incoherent way. It would create heterogeneous groupings.

“As a matter of ordinary language, the provisions relating to sex discrimination, and especially those relating to pregnancy and maternity and to protection from risks specifically affecting women, can only be interpreted as referring to biological sex.”

Trans rights campaigners urged trans people and their supporters to remain calm about the decision.

The campaign group Scottish Trans said: “We are really shocked by today’s supreme court decision, which reverses 20 years of understanding of how the law recognises trans men and women with gender recognition certificates.

“We will continue working for a world in which trans people can get on with their lives with privacy, dignity and safety. That is something we all deserve.”

Ellie Gomersall, a trans woman in the Scottish Green party, called on the UK government to change the law to entrench full equality for trans people.

Gomersall said: “I’m gutted to see this judgment from the supreme court, which ends 20 years of understanding that transgender people with a gender recognition certificate are able to be, for almost all intents and purposes, recognised legally as our true genders.

“These protections were put in place in 2004 following a ruling by the European court of human rights, meaning today’s ruling undermines the vital human rights of my community to dignity, safety and the right to be respected for who we are.”

The gender critical campaign group For Women Scotland, which is backed financially by JK Rowling, said the Equality Act’s definition of a woman was limited to people born biologically female.

Maya Forstater, a gender critical activist who helped set up the campaign group Sex Matters, which took part in the supreme court case by supporting For Women Scotland, said the decision was correct.

“We are delighted that the supreme court has accepted the arguments of For Women Scotland and rejected the position of the Scottish government. The court has given us the right answer: the protected characteristic of sex – male and female – refers to reality, not to paperwork.”

Hodge, the deputy president of the court, said it believed the position taken by the Scottish government and the Equality and Human Rights Commission that people with gender recognition certificates did qualify as women, while those without did not, created “two sub-groups”.

This would confuse any organisations they were involved with. A public body could not know whether a trans woman did or did not have that certificate because the information was private and confidential.

And allowing trans women the same legal status as biological women could also affect spaces and services designed specifically for lesbians, who had also suffered historical discrimination and abuse.

In part of the ruling that could have sweeping implications for policymakers in the sports world and sports centres, he said some services and places could “function properly only if sex is interpreted as biological sex”.

“Those provisions include separate spaces and single-sex services, including changing rooms, hostels, medical services, communal accommodation, [and] arise in the operation of provisions relating to single-sex characteristic associations and charities, women’s fair participation in sport, the operation of the public sector equality duty and the armed forces.”

Hodge urged people not to see the decision “as a triumph of one or more groups in our society at the expense of another”. He said all transgender people had clear legal protections under the 2010 act against discrimination and harassment.

Kishwer Falkner, the chair of the Equality and Human Rights Commission, which had intervened in the case to support the Scottish government’s stance, said it would need time to fully interpret the ruling’s implications.

However, the commission was pleased it had dealt with its concerns about the lack of clarity around single-sex and lesbian-only spaces.

“We are pleased that this judgment addresses several of the difficulties we highlighted in our submission to the court, including the challenges faced by those seeking to maintain single-sex spaces, and the rights of same-sex attracted persons to form associations.”

Donald Trump’s tariffs will send international trade into reverse this year, depressing global economic growth, the World Trade Organization has warned.

In its latest snapshot of the global trading system, the Geneva-based institution says it had previously expected goods trade to expand by a healthy 2.7% this year. As a result of Washington’s trade policy, it is now forecasting a 0.2% decline.

Presenting the forecasts, the WTO’s director general, Ngozi Okonjo-Iweala, said she was particularly concerned about the “decoupling” of the US and China, calling it “a phenomenon that is really worrying to me”.

She said trade between the two geopolitical rivals was expected to plunge by 81% – 91% without exemptions for tech products such as smartphones – saying this was “tantamount to a decoupling of the two economies” and would have, “far-reaching consequences”.

Okonjo-Iweala said the WTO was canvassing its member countries about whether to convene an emergency meeting to discuss the situation.

In its report, the organisation says: “The outlook for global trade has deteriorated sharply due to a surge in tariffs and trade policy uncertainty.” It had previously forecast global GDP growth of 2.8% for 2025, but now expects a weaker 2.2%.

The US has imposed tariffs of 10% on all imports, with much higher rates for China totalling 145%, and on specific sectors including cars and steel. The WTO expects the biggest impact of the policy to be a sharp decline in trade with the US – with other regions still expected to see growth.

Trump’s far larger, “reciprocal” tariffs were paused last week for 90 days after a violent reaction in financial markets. The WTO warns that if these are reimposed after the hiatus, it would have a much greater impact, causing a 0.8% decline in global goods trade.

If this was followed with an upsurge in “trade policy uncertainty” worldwide, as other countries readjust their policies in response, the WTO suggests the effects would then be an even greater 1.5% fall in trade. And in this worst-case scenario, the WTO predicts even weaker global GDP growth, of just 1.7%.

After Trump’s “liberation day” tariff announcement on 2 April was followed by a string of sometimes apparently contradictory statements from Washington, the WTO warns that uncertainty in itself is an important contributor to the risks of a slowdown.

“Uncertainty fosters an increased prudence in decision-making,” the WTO says, pointing to evidence that “trade policy uncertainty can, among other things, dampen business confidence, reducing business investment and thereby impairing economic growth.”

It adds: “Ultimately, the degree to which uncertainty can be managed by firms will be a key determinant of whether the positive macroeconomic momentum observed in 2024 translates into sustained global trade growth in the coming years.”

The WTO predicts some “diversion” of trade, as Beijing seeks new markets for its goods outside the US. Chinese exports to regions outside North America are expected to expand by between 4% and 9%, in 2025.

Services trade is not directly hit by Trump’s tariffs, but the WTO expects it to be affected indirectly. “Tariff induced declines in goods trade weaken demand for related services such as transport and logistics, while broader uncertainty dampens discretionary spending on travel and slows investment-related services,” it warns.

The WTO acts as the watchdog for global trading rules, and has previously provided a forum for the negotiation of international trade deals – but its role has increasingly come into question in recent years, as the progress of globalisation has slowed.

Trump’s tariffs have been applied in complete disregard to the “most favoured nation” rule that forms the bedrock of the system overseen by the WTO – which is meant to mean that trade advantages offered to one member-country should be extended to all.

China has urged the WTO to investigate the impact of the Trump tariffs. Beijing said in a statement to the WTO last week: “Reciprocal tariffs are not – and will never be – a cure for trade imbalances. Instead, they will backfire, harming the US itself.”

Google is being sued in the UK for up to £5bn in damages over allegations it shut out rivals in the internet search market and abused this dominance to overcharge businesses for advertisements.

A class action filed at the competition appeal tribunal on Tuesday argues that the US company has taken actions that enable it to charge higher prices for the promotions that appear in search queries than it otherwise could in a fair market.

It is alleged that Google, which is owned by Alphabet, contracted phone makers to pre-install the Google search app and Chrome browser on Android devices and paid Apple to make it the default search engine on iPhones, with the intention of shutting out competition.

The claim is filed by a competition law expert, Or Brook, on behalf of thousands of businesses and alleges Google ensured its search engine had better functionality and more features for Google’s own advertising offering than that of its competitors.

A Google spokesperson said: “This is yet another speculative and opportunistic case and we will argue against it vigorously. Consumers and advertisers use Google because it is helpful, not because there are no alternatives.”

Brook said businesses had almost no choice but to use Google ads to advertise their products and services.

“Regulators around the world have described Google as a monopoly and securing a spot on Google’s top pages is essential for visibility,” she said in a statement. “Google has been leveraging its dominance in the general search and search advertising market to overcharge advertisers.”

The Competition and Markets Authority launched a UK investigation into Google’s search services in January, which is still ongoing, including into their impact on advertising markets. It said at the time that millions of people and businesses relied on Google’s services, which accounted for 90% of searches and were used by more than 200,000 UK businesses to advertise.

Google is facing several competition investigations and lawsuits around the world that relate to its digital advertising market dominance.

Since September, it has been embroiled in a second antitrust trial in the US over whether it has illegally monopolised the digital advertising industry, after losing a landmark case in August, which it is appealing against.

One Google ad executive quoted in the US government’s complaint compared the company’s business model to Goldman Sachs or Citibank owning the New York Stock Exchange.

A loss in that trial could force Google to break up parts of its business and divest some of its advertising technology, hitting its primary source of revenue. It would also have far-reaching implications for the wider tech industry and online publishers.

In March, the European Commission accused Google of breaking its competition rules for digital markets by prioritising search engine results that pointed to Alphabet’s own services over those of rivals, breaching the requirement to treat third-party services in a “transparent, fair and non-discriminatory” way.

Breaches of the EU’s Digital Markets Act can result in companies being fined 10% of worldwide revenue, or 20% if they reoffend.

Donald Trump has been seeking to press governments and institutions into dropping competition lawsuits against tech companies by indicating that he will factor any regulatory action against US companies into his decisions about imposing sweeping tariffs on foreign goods.

It emerged this month that the UK government was considering a reduction in the headline rate of its digital services tax – a 2% levy introduced in 2020 on the revenues of tech companies including Amazon, Google and Apple that raises about £800m a year – in an attempt to placate the US president.

French tennis player Lois Boisson has responded to Harriet Dart’s on-court claim that “she smells really bad” with a social media post that pokes fun at the incident.

During a change of ends in Tuesday’s match at the Rouen Open, Dart asked the umpire: “Can you tell her [Boisson] to wear deodorant because she smells really bad?” Her comments were picked up by a courtside microphone and quickly attracted attention and criticism on social media.

Dart later apologised on Instagram for the comments made during her 6-0, 6-3 defeat to Boisson, who responded on the same platform. The 21-year-old posted an edited image of herself on court holding a can of Dove deodorant. “@dove apparently need a collab,” wrote the Frenchwoman, accompanied by two laughing emojis.

Boisson, who is ranked No 303 in the world and entered the event as a wildcard, will face Japan’s Moyuka Uchijima, who beat Italy’s Nuria Brancaccio 3-6, 6-2, 6-1 on Wednesday, in the last 16. Dove have yet to officially respond to Boisson’s suggestion of an online collaboration.

After the incident, Dart posted an apology on her Instagram story. “Hey everyone, I want to apologise for what I said on court today, it was a heat-of-the-moment comment that I truly regret,” Dart said.

“That’s not how I want to carry myself, and I take full responsibility. I have a lot of respect for Lois and how she competed today. I’ll learn from this and move forward.”

The Australian tennis star Nick Kyrgios, who is no stranger to controversy himself, weighed in on the debate on X, writing: “Saying this when you are down and getting snipped is wild”.

Members of the Board of Deputies, the largest body representing British Jews, have said they can no longer “turn a blind eye or remain silent” over the war in Gaza.

In a significant break with the board’s customary support for the Israeli government, the 36 signatories to an open letter published in the FT say “Israel’s soul is being ripped out”.

Since the war began after the terrorist atrocities committed by Hamas against Israelis on 7 October 2023, statements by the Board of Deputies of British Jews have been broadly supportive of the Israeli government.

But the letter, signed by about one in eight of the board’s members, is highly critical of recent actions by the Israeli government.

It says: “The inclination to avert our eyes is strong, as what is happening is unbearable, but our Jewish values compel us to stand up and to speak out.”

Last month, after a pause in fighting during which dozens of Israelis held hostage in Gaza were released, the Israeli government “chose to break the ceasefire and return to war in Gaza … Since then, no hostages have returned. Hundreds and hundreds more Palestinians have been killed; food, fuel and medical supplies have once again been blocked from entering Gaza; and we are back in a brutal war where the killing of 15 paramedics and their burial in a mass grave is again possible and risks being normal.

“Such incidents are too painful and shocking to take in, but we know in our hearts we cannot turn a blind eye or remain silent at this renewed loss of life and livelihoods, with hopes dwindling for a peaceful reconciliation and the return of the hostages.

“This most extremist of Israeli governments is openly encouraging violence against Palestinians in the West Bank, strangling the Palestinian economy and building more new settlements than ever … Israel’s soul is being ripped out and we, members of the Board of Deputies of British Jews, fear for the future of the Israel we love and have such close ties to.”

The letter adds: “Silence is seen as support for policies and actions that run contrary to our Jewish values. Led by the families of the hostages, hundreds of thousands of Israelis are demonstrating on the streets against the return to war by an Israeli government that has not prioritised the return of the hostages. We stand with them. We stand against the war … It is our duty, as Jews, to speak out.”

One of the signatories, Philip Goldenberg, a lawyer, said the Israeli government had “absolutely adopted the Trump playbook”, including demonising those who disagreed with it. “That is not what Israel is about,” he told the BBC’s The World at One.

There was a “whole range of views” among British Jews, “and there are those who think we should not have done this”, he said. There were others who shared the views expressed in the letter but “don’t want to put their heads above the parapet”.

What was happening in Gaza was “a total breach of Jewish ethical values”, he added. “More damage is being done to the Zionist project by Netanyahu than Hamas could ever achieve.”

A spokesperson for the Board of Deputies said other members would “no doubt put more emphasis on the fundamental responsibility of Hamas for this ghastly situation and the need to ensure that they are prevented from ever repeating the heinous crimes of 7 October”.

Within the diversity of views among British Jews, “however, there is much unity”, the spokesperson added. The UK Jewish community wanted to see Hamas release the remaining hostages, aid flowing in to Gaza and “definitive progress towards lasting peace and security for Israelis, Palestinians and the wider Middle East”.

Members of the Board of Deputies, the largest body representing British Jews, have said they can no longer “turn a blind eye or remain silent” over the war in Gaza.

In a significant break with the board’s customary support for the Israeli government, the 36 signatories to an open letter published in the FT say “Israel’s soul is being ripped out”.

Since the war began after the terrorist atrocities committed by Hamas against Israelis on 7 October 2023, statements by the Board of Deputies of British Jews have been broadly supportive of the Israeli government.

But the letter, signed by about one in eight of the board’s members, is highly critical of recent actions by the Israeli government.

It says: “The inclination to avert our eyes is strong, as what is happening is unbearable, but our Jewish values compel us to stand up and to speak out.”

Last month, after a pause in fighting during which dozens of Israelis held hostage in Gaza were released, the Israeli government “chose to break the ceasefire and return to war in Gaza … Since then, no hostages have returned. Hundreds and hundreds more Palestinians have been killed; food, fuel and medical supplies have once again been blocked from entering Gaza; and we are back in a brutal war where the killing of 15 paramedics and their burial in a mass grave is again possible and risks being normal.

“Such incidents are too painful and shocking to take in, but we know in our hearts we cannot turn a blind eye or remain silent at this renewed loss of life and livelihoods, with hopes dwindling for a peaceful reconciliation and the return of the hostages.

“This most extremist of Israeli governments is openly encouraging violence against Palestinians in the West Bank, strangling the Palestinian economy and building more new settlements than ever … Israel’s soul is being ripped out and we, members of the Board of Deputies of British Jews, fear for the future of the Israel we love and have such close ties to.”

The letter adds: “Silence is seen as support for policies and actions that run contrary to our Jewish values. Led by the families of the hostages, hundreds of thousands of Israelis are demonstrating on the streets against the return to war by an Israeli government that has not prioritised the return of the hostages. We stand with them. We stand against the war … It is our duty, as Jews, to speak out.”

One of the signatories, Philip Goldenberg, a lawyer, said the Israeli government had “absolutely adopted the Trump playbook”, including demonising those who disagreed with it. “That is not what Israel is about,” he told the BBC’s The World at One.

There was a “whole range of views” among British Jews, “and there are those who think we should not have done this”, he said. There were others who shared the views expressed in the letter but “don’t want to put their heads above the parapet”.

What was happening in Gaza was “a total breach of Jewish ethical values”, he added. “More damage is being done to the Zionist project by Netanyahu than Hamas could ever achieve.”

A spokesperson for the Board of Deputies said other members would “no doubt put more emphasis on the fundamental responsibility of Hamas for this ghastly situation and the need to ensure that they are prevented from ever repeating the heinous crimes of 7 October”.

Within the diversity of views among British Jews, “however, there is much unity”, the spokesperson added. The UK Jewish community wanted to see Hamas release the remaining hostages, aid flowing in to Gaza and “definitive progress towards lasting peace and security for Israelis, Palestinians and the wider Middle East”.

China has accused UK politicians of “arrogance, ignorance and a twisted mindset” as it defended British Steel’s owner, Jingye, after a barrage of criticism over the narrowly averted shutdown of its blast furnaces.

Beijing’s embassy to the UK accused unspecified British public figures of slandering China’s government and businesses, in comments published on Wednesday on its website.

It followed criticism of the actions of Jingye, British Steel’s Chinese owner since 2020, by the business secretary, Jonathan Reynolds. Reynolds accused Jingye of not acting in good faith after it threatened to shut down British Steel’s furnaces at Scunthorpe within days, with the loss of 2,700 jobs.

The government stepped in on Saturday to avoid the shutdowns with emergency legislation to take control of British Steel.

The dispute over the future of the Scunthorpe furnaces has threatened to worsen the UK’s already troubled relationship with China, even as the Labour government seeks to boost inward investment.

China’s embassy said politicians objecting to the country’s involvement in the UK steel sector “took the opportunity to attack all Chinese companies and the Chinese government”, after a warning by the country’s foreign ministry earlier on Monday against “politicising” the situation.

In an unusual question-and-answer format, the embassy wrote: “The anti-China rhetoric of some individual British politicians is extremely absurd, reflecting their arrogance, ignorance and twisted mindset.”

Jingye was approached by the Conservative government in 2019 to take over British Steel after its previous owner, the private equity firm Greybull Capital, walked away. British Steel has lost more than £350m since then. Jingye said last month it would close the blast furnaces, and it turned down an offer of £500m in UK government support to switch from the polluting blast furnaces to cleaner electric arc furnaces.

Reynolds said the UK had “got it wrong in the past” about allowing Chinese investment in strategically important industries such as steel, and highlighted the influence of the Chinese government on private companies. “I wouldn’t personally bring a Chinese company into our steel sector,” he said on Sunday.

However, the British government has been sending mixed messages on Chinese investment. The chancellor, Rachel Reeves, visited China in January to try to drum up investment, and Reynolds is due to visit the country later this year, despite his criticisms.

The embassy credited Jingye with saving workers’ jobs in 2020 and said it was “a normal decision” by the company to close the blast furnaces, adding that the dispute could hit Chinese investment in the UK. It contrasted the treatment of China with the alleged lack of criticism of Donald Trump’s tariffs. The embassy wrote: “What on earth are they up to?”

“Any words or deeds that politicise or maliciously hype up business issues will undermine the confidence of Chinese business investors in the UK and damage China-UK economic and trade cooperation,” it added.

The UK’s Department for Business and Trade was approached for comment.

Tens of thousands of Spotify users around the world have reported being unable to stream music on the app.

Downdetector, which tracks platforms, showed more than 48,000 outage reports for Spotify worldwide at on Wednesday afternoon.

In the UK, the number of people reporting that Spotify was not functioning peaked at about 1.30pm, after problems began 30 minutes earlier. By 3pm, the number had fallen to about 10,000.

Spotify wrote on X: “We’re aware of some issues right now and are checking them out.”

The Sweden-based streaming platform did not provide further information on what has caused the problem, or for how long its services may be affected.

Spotify, which has more than 675 million users worldwide, told the BBC “the issue with search has been addressed” and it was rolling out an update to its users.

Users said they were still able to play music they had downloaded on to their devices, however they were unable to view artists or use the search function on the app. Others said the platform was slow or unresponsive.

After trying to search for music, Spotify appears to time out, displaying the message “something went wrong” with a refresh button.

Many users expressed their frustration on social media, including that the outage had interrupted their gym sessions or study routines.

Teachers will not have to inform on sexually active teenagers under a new legal duty to report child abuse after a novel “Romeo and Juliet” exemption received cross-party support.

A new crime and policing bill obliges professionals in England, including teachers and healthworkers, to report suspicions of child sexual abuse to the police or local authority in an attempt by the government to prevent cover-ups.

There will be dispensation, however, when it comes to teenagers in consensual sexual relationships, including when it involves a 17-year-old boy and a 14-year-old girl, after Harriet Cross, a Conservative whip, indicated that her party backed what she described as “a Romeo and Juliet exemption”.

The age of sexual consent in the UK is 16 and, unlike in other countries such as Australia, there is no exemption allowing sexual activity between under 18s, even when the two minors are in a consensual relationship.

The crime and policing bill introduces the concept of such a close-in-age exemption by asking professionals to use their judgment when it comes to whether they need to report cases involving teenagers found to be sexually active, inciting each other to engage in such activity or engaging in it in front of a child.

In order to be covered by the exemption from the duty to report, teachers and other professionals need to be confident that the individuals are both over the age of 13 and that there are no concerns about any abuse or coercion in the relationship.

The clause received support from the Conservatives at the committee stage of the bill’s parliamentary journey towards becoming law.

Speaking before the crime and policing bill committee, Cross, who was elected for the first time to parliament in 2024, told MPs that the exemption “recognises that not all sexual activity involving under-18s is a cause for alarm or state intervention”.

She said: “Sexual activity for under-16s is, as we know, illegal in law but without this clause, a teacher who learns of two 15-year-olds in a consensual relationship would legally be bound to report that as a child sexual offence.

“The clause empowers the teacher to use their professional judgment, but the exemption applies only where the reporter is satisfied that the relationship really is consensual and not appropriate to report given the circumstances.

“The bar for not reporting should be high. As a safeguard, the clause explicitly says to consider the risk of harm. If there is any indication of harm or imbalance, the duty to report remains.

“For example, if a 14-year-old girl is sexually involved with a 17-year-old boy, even if she says she has consented, a teacher or adult might rightly feel uneasy about the power dynamic and the possible impact of grooming. The adult might decide that it is appropriate to report in that case.”

Cross said the exemption was “not about condoning underage sex; it is about proportionality”.

She added: “We do not want to criminalise young people unnecessarily or deter them from seeking healthcare or advice … It mirrors, for instance, the approach in some Australian states where similar laws exist. Those states carve out consensual peer activity from mandatory reporting to avoid inundating child protection with consensual cases.”

Speaking for the government, Jess Phillips, the minister for safeguarding, said she did not want to deter young people from being open about their relationships and accessing services.

“This avoids situations such as two kissing teenagers having to be reported to the authorities by a teacher who knows them both well,” she added. “That is not something I want to have to deal with: teenagers kissing in halls. I suppose it is better working here [in parliament]. Well done to the teachers of the world. For the record, I do not want to see anyone kissing in the corridors – teenagers or otherwise.”

Under the new law, those who fail to comply with the “duty to report” will be liable for sanctions from their professional regulator or the Disclosure and Barring Service.

It will only be if someone deliberately tries to stop a report of child sexual abuse that criminal sanctions will apply, which could lead to up to seven years in prison.

Researchers are claiming a breakthrough in lab-grown meat after producing nugget-sized chunks of chicken in a device that mimics the blood vessels that make up the circulatory system.

The approach uses fine hollow fibres to deliver oxygen and nutrients to chicken muscle cells suspended in a gel, an advance that allowed scientists to grow lumps of meat up to 2cm long and 1cm thick.

The hollow fibre bioreactor paves the way for whole cuts of chicken, beef, pork and fish to be grown in the lab, researchers believe. The same technology has the potential to produce functional organs, too.

“This looks like a transformative step, it’s a really elegant solution,” said Prof Derek Stewart at the James Hutton Institute in Dundee. “They’ve created something of a size and scale that people are hardwired to eat: it’s the chicken nugget model.”

A major hurdle to growing meat in the lab is the difficulty in getting enough nutrients and oxygen to muscle cells in thick sections of tissue. Without them, the cells die off. As such, many projects focus on growing tiny pieces of meat akin to mince.

To solve the size problem, Prof Shoji Takeuchi, at the University of Tokyo, built a bioreactor that holds living cells in a gel and feeds them with oxygen and nutrients through fine, semi-permeable fibres that pass through the material.

“One of the key challenges in growing thick tissue is that cells in the centre can struggle to receive enough oxygen and nutrients, which may lead to cell death,” Takeuchi said. “Our system helped address this by providing internal perfusion, allowing us to support the growth of thicker, more consistent tissue.”

Writing in Trends in Biotechnology, Takeuchi and his team describe how they grew an 11g chunk of chicken from a gel that had more than 1,000 hollow fibres running through it. A culture medium rich in nutrients and oxygen was pumped down the fibres to nourish the cells.

Growing meat in larger, more structured pieces could help researchers replicate the texture and appearance of meat such as chicken breast or thigh, Takeuchi said. “While small-scale or minced cultured meat is easier to produce, it may not fully capture the fibrous structure and mouth-feel that consumers associate with conventional cuts,” he added.

For now, the hollow fibres of the artificial circulatory system must be removed by hand once the meat has grown. But the scientists are aiming to replace them with edible cellulose fibres that can be left in and used to vary the texture of the meat.

Edible fibres may open up other possibilities, too, Stewart said. Meats could be fortified by adding zinc and selenium to the culture medium, helping to boost the immune systems of older people, he suggested. He also wondered if masala sauce could be passed down the tubes to create a nugget version of chicken tikka masala. “I’d give it a go,” he said.

Takeuchi said future versions of the bioreactor may need artificial blood that carries more oxygen to the cells, to allow the growth of larger lumps of meat. With sufficient funding, he believes products based on the approach could be available in five- to 10 years.

“At first, it will likely be more expensive than conventional chicken, mainly due to material and production costs,” he said. “However, we are actively developing food-grade, scalable systems, and if successful, we expect the cost to decrease substantially over time.”