The Labour government has been complicit in crimes committed by Israel in Gaza and in the desecration of international law, according to an unoffical tribunal on Gaza chaired by the former party leader Jeremy Corbyn and two specialists in international law.

The tribunal’s findings to be published on Monday are likely to be cited in May’s local elections, in which Labour faces a rearguard action to beat off challenges from the Greens and Your Party, in part driven by anger that the government has not done enough to back the Palestinian cause.

The tribunal took evidence from lawyers, medical professionals, former Foreign Office officials and Palestinians, and focused largely on whether the UK should have done more to end its cooperation with Israel to avoid being accused of failing to meet its duty to prevent a genocide.

It finds that the government should have ended all arms exports to Israel, stopped sharing intelligence and reviewed its trade relations with the country, especially after the international court of justice (ICJ) said in a July 2024 advisory opinion that Israel was occupying Palestine unlawfully.

The tribunal’s report reads: “Britain’s failure to meet its legal obligations has contributed to the mass killing of Palestinian civilians and the wholesale destruction of civilian objects, the desecration of international law and the further erosion of Britain’s status as a nation committed to the rule of law in the international arena.”

It says the UK not only failed to meet its duty to seek to prevent a genocide, but in some instances actively participated in such acts.

The Foreign Office says it has imposed three sets of sanctions in response to settler violence in the West Bank and opposes all forms of forced displacement.

The Middle East minister, Hamish Falconer, told MPs earlier this month that the government “was due to update parliament on the wider issues posed by the ICJ advisory opinion”. “There must be accountability and justice for all crimes committed right across Palestinian and Israeli territory,” he said.

The ICJ has not yet had a full hearing on whether a genocide was committed in Gaza, but it said in January 2024 that there was a real and imminent risk of irreparable prejudice to Palestinians’ rights to be protected from acts of genocide.

The two co-chairs of the tribunal were Dr Shahd Hammouri, a lecturer in international law at the University of Kent, and Neve Gordon, a professor of human rights law at Queen Mary University of London.

Much of the report focuses on the legal duties that the ICJ rulings placed on the government. It concludes that the January 2024 finding placed all states on clear notice that their duty under the Geneva conventions to prevent genocide had been engaged, and doing so required “more than expressions of concern”.

The fundamental duty should not be superseded by contractual obligations to US arms manufacturers, or by stating that no definitive conclusion had been reached by international courts, it says.

The 112-page report also claims the ICJ advisory opinion on the unlawfulness of the Israeli occupation of Palestine placed a legal duty on the UK and other states to abstain from entering into trade dealings with Israel concerning the occupied territories, especially if the trade might entrench its “unlawful presence”.

In his preface, Corbyn says the report “will help cement Labour’s legacy as an active participant in one of the great crimes of our time”.

The tribunal, drawing on evidence compiled in a UN domestic court case brought by the Global Legal Action Network, found the government had imposed a requirement on itself to ask Israel for justification of specific attacks in Gaza, leading it to conclude that a breach of international humanitarian law had definitively occurred in only one of the 413 cases examined.

The report says its perverse self-imposed methodology “required the government to examine the impact of an individual strike on a hospital, but not the lawfulness of the decimation of the whole healthcare system”.

In evidence cited by the tribunal, Falconer told MPs that reaching a conclusion about individual incidents required specific sensitive information “such as the intended targets, anticipated military advantage and anticipated civilian harm, which is often not available to us”.

The tribunal recommends the government release all licensing data, publish all legal advice concerning its obligation to prevent genocide, set up a full public inquiry and provide the ICJ with all the surveillance footage it compiled during RAF overflights of Gaza.

The tribunal’s findings are likely to be used by the left to attack Labour in the local elections. A Vote Palestine 2026 campaign backed by the Palestine Solidarity Campaign (PSC) is calling for Gaza to be on the ballot paper given that local councils invest billions in Israel. So far 1,200 council candidates have signed the PSC’s commitment to Palestine.

Local pacts are being encouraged in which independents and local Green parties cooperate to target Labour councillors. Your Party, of which Corbyn is the parliamentary leader, said it would be “campaigning loudly on Gaza and Palestine including by calling on councils to divest from Israel”.

A university regulator in England has failed to investigate potential breaches of laws protecting academic freedom at a dozen theological colleges and is now facing legal action, the Guardian has learned.

The National Secular Society says it is preparing to pursue the Office for Students (OfS) through the courts to act on complaints first made five years ago, arguing that the colleges are ineligible for public funding or government-backed student loans because of their commitment to theological doctrine.

The society said the 12 bible or theological colleges received more than £80m through the government-backed Student Loans Company and £1m in funding from the OfS since 2018.

The OfS said it was unable to comment due to the pending legal action, but Stephen Evans, the NSS’s chief executive, said his organisation had become frustrated at the OfS’s refusal to respond or act, despite multiple contacts and meetings with the regulator since 2021.

Evans said: “It’s a case of the regulator not doing its job properly. These colleges don’t appear consistent with the OfS requirements on academic freedom and freedom of expression, so they shouldn’t have been registered in the first place.

“The lack of transparency is striking. If institutions are built around enforcing a confessional worldview rather than academic freedom, then they shouldn’t be registered by the OfS or receiving public funds.

“Since we’ve raised this with the OfS, as far as we can tell, nothing appears to have been done about it.”

Higher education providers in England must register with the OfS to access student loans, and are required to uphold freedom of speech and academic freedom.

The NSS has told the OfS that it will seek a judicial review to reveal what action it has taken against the colleges, including one whose “college law” included a provision: “To promote the fear of the Almighty God through education and information dissemination.” Another college’s code of conduct for students lists “sexual intercourse outside of marriage” as grounds for disciplinary action.

The legal action comes as the OfS is waiting on a crucial high court judgment on its investigation into the University of Sussex, after the OfS fined Sussex a record £585,000 for alleged breaches of regulations.

The NSS’s action is supported by Prof Chris Higgins, a former vice-chancellor of Durham University, who said the complaint does not apply to theological colleges, such as those run by the Church of England, which are not registered with the OfS.

“As far as we are concerned the OfS made a mistake in registering these independent bible colleges in the first place because their governing documents specifically restrict academic freedom and freedom of speech,” Higgins said.

“Many of these bible colleges [also] offer degrees which have nothing to do with training for the ministry … such as courses in business or the performing arts. Yet they still require students and staff to adhere to a statement of faith and worship together – something which has recently been outlawed as indoctrination by the supreme court in relation to communal worship in schools in Northern Ireland.”

The NSS’s pre-action letter to the OfS mentions three of the colleges: Moorlands College in Dorset; Regents Theological College, a training centre of the Elim Pentecostal church in Malvern; and Christ the Redeemer College in Harrow.

The Rev Michelle Nunn, principal of Regents Theological College, said: [The college] seeks to operate in accordance with UK equality and freedom of speech legislation and the Office for Students regulations. Students are admitted based on academic criteria and choose to study with us because our programmes align with their academic and vocational interests.

“We encourage robust intellectual inquiry and debate in our classes and welcome respectful engagement with differing perspectives.”

Moorlands College and Christ the Redeemer College did not take up offers to respond after being contacted by the Guardian.

Democratic US senator Cory Booker has criticized both his own political party as well as its Republican counterpart for being “feckless” in ceding congressional war powers to Donald Trump, saying that their decision could embolden the president to unilaterally attack Cuba, North Korea and other countries.

“I’m going to be one of those Democrats [who] say I think both parties have been feckless in allowing the growth of the power of the presidency,” Booker said on Sunday on CNN’s State of the Union.

The New Jersey senator said nothing Barack Obama did while in the White House – or that even Trump did before his first presidency ended in defeat to Joe Biden – was “in any way related to what we’re seeing right now”.

Booker’s comments alluded to US military strikes Trump has ordered in Nigeria, Venezuela and Iran since Christmas. He called the war that the US and Israel started in Iran on 28 February – when a missile strike killed Iranian supreme leader Ayatollah Ali Khamenei – “the biggest military engagement of our country since the war in Afghanistan”.

Meanwhile, during that stretch, Trump has also renewed threats to seize Greenland for the US by military force if necessary.

Booker’s fellow Democrats in the US House put forth a measure calling for a stop to US military action in Iran. But without support from members of Trump’s Republican party, the measure failed, and the military campaign in Iran has continued.

One day prior, the US Senate rejected a war powers resolution in a 47-53 vote that largely followed party lines.

Booker pointed to how the spiraling conflict has not only roiled regional stability but oil markets as well. The strait of Hormuz, a waterway crucial to world trade, has been closed for two weeks as of Sunday.

“Literally, you see with what’s going on in the strait of Hormuz right now as the biggest gumming up of the oil markets we have ever seen,” Booker said to CNN. “The consequences strategically for us moving so many assets in the region means that we’re endangering the assets we have necessarily and potentially in other areas.”

Booker alluded to the deaths of 13 US military members amid reported as of Sunday amid the Iran conflict, saying: “This is a massive military undertaking, costing American taxpayers billions and billions of dollars and tragically costing 13 lives.”

He recognized that previous presidents had strayed from limits on their power to engage in war but maintained Trump’s Iran campaign had exceeded that precedent.

“At this magnitude, at this cost, why is Congress just laying down and doing nothing?” Booker said. “Because, if we allow this to happen, then we give Trump the permission to say, ‘OK, finished with Venezuela, I went to Iran, now I’m going to go to Cuba, now I’m going to go to North Korea.’

“It is outrageous and never conceived of that we could have this level of a military engagement without the people’s house, Congress, doing something about it.”

Twelve people were arrested as hundreds joined a pro-Palestinian al-Quds Day demonstration on one side of the Thames, while hundreds more gathered on the opposite bank to back Israeli and American attacks on Iran.

At least 1,000 police officers were drafted in to keep the two rival protests apart. Lambeth Bridge, the nearest river crossing to each rally, remained closed on Sunday afternoon.

The Metropolitan police assistant commissioner Ade Adelekan said: “We made 12 arrests including for showing support for a proscribed organisation, affray and for threatening or abusive behaviour. We are also investigating chants made by a speaker at the al-Quds protest.”

The home secretary, Shabana Mahmood, granted a police request to ban al-Quds protesters from marching, for the first time since 2012. She said: “I expect to see the full force of the law applied to anyone spreading hatred and division instead of exercising their right to peaceful protest.”

Police warned the al-Quds demonstrators on the Albert Embankment that they would arrest those displaying placards, flags or chanting that “cross the line into hate crime or support of a proscribed organisation”.

Some did carry placards of Iran’s new supreme leader, Mojtaba Khamenei, or his father and predecessor, Ali Khamenei, who was killed on the first day of the war.

There was also a heavy police presence over the Thames at Millbank at a counterprotest co-organised by Stop the Hate and the Lion Guard of Iran group.

Some protesters carried both an Israeli flag and the flag of the Iranian state before the 1979 Islamic revolution to show support for Reza Pahlavi, the son of Iran’s former pro-western monarch.

Georgie Stagg, 70, a retired arts administrator from Lewisham who was wearing a Palestinian keffiyeh, walked past the pro-Israeli demonstration on her way to the al-Quds rally. She was quickly moved on by a police officer, who said: “Because of what you are wearing, unfortunately I’m going to have to ask you to move that way.”

Stagg said: “We’ve marched on al-Quds Day for 40 years, and I have never seen any trouble. There was friction last year, but that’s because the pro-Israel people were down at Parliament Square, along with a lot of far right who were causing the trouble.”

Stagg added: “You can’t criticise the Iranian government for being anti-democratic when we’ve got a government here that’s arresting people holding placards. We were told you couldn’t say ‘from the river to the sea’, and you can’t say global intifada – that just means uprising.”

The rival demonstrations exposed bitter divisions between Iranians in the UK. One of the pro-Israeli protesters carried a banner saying: “Qud you take your terrorism and fuck off.”

Raham Moshami 52, fled Iran in 2010 after being tortured in jail. She showed scars on her forehead as proof. “We are here to support our people, because the Iranian government is holding my people hostage,” she said.

She added: “Netanyahu and Trump are trying to help us. We have to remove a cancer, because the Iranian government is like a cancer. Pahlavi is a good man, he’s very educated.”

Moshami also dismissed the al-Quds demonstrators as being in the pay of the Iranian government, without offering any evidence for the claim.

On the other side of the Thames, Fereydun Bahrami, 71, had travelled by coach from Glasgow with 50 other Iranians to join the al-Quds protest, which is named after the Arabic name for Jerusalem and was organised by the Islamic Human Rights Commission.

“We are here to celebrate al-Quds Day and also protest against the war,” he said. Bahrami, who left Iran to study engineering in Glasgow where he went on to run a metalworks, was carrying a placard that read “Stop Using UK bases to bomb Iran”.

Gesturing across the river he said: “They are brainwashed to support Israel, rather than their families under bombardment.”

He added: “I’m very sad about this war. At the beginning America killed 168 girls in a school. For the last 47 years Iran hasn’t attacked anyone.”

Bahrami objected to government ministers suggesting the demonstration was a hate march. “This is a love walk, how can it be a hate march?” he said. “We love human beings. We love Jewish people. We are Muslims, we are bound by religion to love everybody else. There is no hate in this crowd here.”

Salma, 60, who works for a freight company in London, said she supported Iranian retaliation against targets in the Gulf. She said: “Fighting back and standing up to the Americans is right – Trump had no right to go in and take out an 86-year-old leader.”

She added: “You can’t have one side being allowed to bomb schools and then worry about ships waiting in the strait of Hormuz. If petrol prices are going up, who cares? Because at the end of the day, this was created by the US.”

Adelekan said fewer people attended the march than anticipated due to the restrictions. “Our policing plan worked, with both groups kept apart and we saw no attempts from either side to breach conditions by marching. Both sets dispersed as planned from 1500 hours,” he said.

“The restrictions and conditions meant many people chose to stay away and not to attend the protest or counterprotest.”

Pakistan has targeted militant hideouts in Afghanistan’s Kandahar province overnight, as the fighting that erupted between the two neighbours late last month showed no signs of abating.

The cross-border attacks, which have included Pakistani airstrikes in Kabul, are the deadliest yet between the countries. Islamabad has referred to the conflict as an “open war”, adding to concerns about regional stability as the US-Israeli conflict with Iran engulfs the Middle East and beyond.

In a post on X, Pakistan’s information minister, Attaullah Tarar, said the military had struck equipment storage facilities and “technical support infrastructure” in the attacks.

The Afghan government spokesperson, Zabihullah Mujahid, said Pakistan had hit two locations: a site used by security guards during the day that was empty at night and a drug rehabilitation centre that suffered slight damage. He said there were no casualties, but that the strikes showed Pakistan was “continuing to invade and fuel the fire of war”.

Afghanistan’s defence ministry said it carried out an attack on an army camp in Pakistan’s South Waziristan area on Sunday in retaliation for the strikes in Kandahar. It claimed the attack destroyed most of the camp’s command centre and other facilities, and inflicted heavy casualties on the Pakistani military.

Pakistan’s information ministry rejected the claims as “propaganda”, saying that a small drone was struck down and that “no military installation or infrastructure was hit”.

Afghanistan also said it carried out operations inside Pakistan across the border from Kunar and Nangarhar provinces, claiming to have captured a Pakistani military outpost and killed several soldiers. Pakistan also rejected those claims.

Pakistan accuses Afghanistan’s Taliban rulers of harbouring militant groups, particularly the Pakistani Taliban, or Tehreek-e-Taliban, which has staged attacks in Pakistan. Afghanistan denies the charge, insisting it does not allow its territory to be used against other countries.

The latest fighting erupted in late February, when Afghanistan launched a cross-border attack into Pakistan in retaliation for Pakistani airstrikes inside Afghanistan days earlier that it said had killed only civilians. The clashes upended a ceasefire that had been brokered by Qatar last October after fighting that had killed dozens of soldiers, civilians and suspected militants.

On Sunday, a mortar fired from Afghanistan destroyed a home in Bajaur, a district in northwestern Pakistan, killing at least four members of the same family and wounding two others, the local government official Adnan Khan said.

Both sides have accused the other of targeting civilians and dozens have been killed. Pakistan’s president, Asif Ali Zardari, on Saturday said Afghanistan’s government had “crossed a red line” by launching drone attacks on civilian areas in Pakistan, and hours later the country reportedly conducted strikes on an Afghan drone storage facility.