Britain’s ongoing arms sales to Israel have provoked bitter infighting within the Conservative party, as Rishi Sunak came under mounting pressure to halt weapons exports in light of the growing humanitarian crisis in Gaza. Amid continued international anger after an Israeli drone strike killed seven aid workers in Gaza, Nicholas Soames, the veteran Tory peer, said the UK should send a message about Israel’s actions – the latest in a series of Conservative figures to call for an end to UK arms sales. As Downing Street and David Cameron, the foreign secretary, remained largely silent, a furious row broke out over Israel’s actions, with the former minister Alan Duncan lambasting what he called pro-Israel “extremists” within the Tories, prompting the party to investigate his comments. Keir Starmer also faces pressure to back an end to arms sales after Sadiq Khan, the London mayor, and Margaret Beckett, the Labour MP who was foreign secretary under Tory Blair, called on the government to consider immediate action. Soames, a former minister who spent 36 years in the Commons before being made a peer, said that in the wake of the deaths of seven aid workers for World Central Kitchen, among them three Britons, the UK needed to stop providing Israel with arms. He told the Guardian: “It’s probably time that that happened now, yes, I think if we’re determined to show that we are not prepared to countenance these ongoing disasters. Israel have every right to go after Hamas, there’s no shadow of doubt about that.” The UK’s contribution to Israel’s arsenal “would be tiny and it’s probably parts more than anything else”, Soames said, adding: “I think it is the message that matters.” Soames joins his fellow Conservative peer Hugo Swire and three Tory MPs – David Jones, Paul Bristow and Flick Drummond – in calling for arms sales to be suspended. A fourth Tory MP, Mark Logan, called on Thursday for the UK’s arms exports to Israel to be reviewed. “We need to seriously reassess any weapon materials/arms exports to Israel in light of what has happened,” he said in a post on X. In contrast, the former home secretary Suella Braverman argued on Thursday that Israel was “absolutely not” in breach of international law. She told BBC Radio 4’s Today programme: “The suggestion itself is absurd and, frankly, an insult to Israel who have been going above and beyond the necessary requirements to ensure that civilian casualties are limited, to ensure that aid is received on to the Gaza Strip and distributed.” Braverman was among a series of Tories subsequently targeted by Duncan. The ex-MP, who served as a foreign minister and an aid minister before stepping down in 2019, said Braverman, as well as Tom Tugendhat, the security minister, and the peer and former cabinet minister Eric Pickles, should be expelled from the Conservatives. Speaking to LBC, Duncan accused Pickles and another Tory peer, Stuart Polak, of “exercising the interests of another country” by lobbying for Israel through the Conservative Friends of Israel group, which Polak formerly headed. In a later interview with Times Radio, Duncan said other Tory MPs and ministers –including Michael Gove, Oliver Dowden, Braverman, Robert Jenrick and Priti Patel – were also extremists for not condemning illegal Israeli settlements on Palestinian land. Some people in the party “refuse to condemn settlements and therefore are not supporters of international law”, Duncan said. “I think the time has come to flush out those extremists in our own parliamentary politics and around it.” The Board of Deputies of British Jews said Duncan’s comments “effectively accuse two Conservative peers, one of whom is Jewish, of dual loyalties” and described this as “disgraceful”. A Conservative spokesperson told the Guardian that Duncan would be investigated by the party over the remarks. Duncan responded by saying anyone who sought to take action against him would find it “proves dangerously harmful to their own reputation”. With the government remaining opaque on its legal advice about Israel’s conduct after the 7 October massacre by Hamas, a fourth former supreme court justice has signed a letter arguing that the government is breaching international law by continuing to arm Israel. Lord Robert Carnwath, who served on the supreme court from 2012 to 2020, was among another 200 lawyers to sign the letter, taking the total to about 800. Its signatories include the supreme court’s former president Lady Hale. It comes after the Guardian published a letter from senior lawyers and judges warning that the UK government was breaching international law by continuing to arm Israel. Separately, the former head of MI6 said Israel’s actions in Gaza had “bordered on the reckless”. Alex Younger, who led the Secret Intelligence Service between 2014 and 2020, said it was “hard not to conclude that insufficient care is being paid to the collateral risks of these operations, one way or another”. Lord Cameron refused to answer questions about Israel and Gaza when interviewed by the BBC on Thursday morning or during media questions at a meeting of Nato foreign ministers in Brussels. Downing Street has given no indication that it plans to halt sales, or of when any legal opinion might be released. According to Israel’s Channel 13 News, during Sunak’s conversation with Benjamin Netanyahu on Tuesday evening, he warned the Israeli prime minister that if more aid did not reach Gaza soon, the UK would formally declare Israel to have breached international law, which could have consequences for weapons sales. In a video interview with the Sun on Wednesday evening, Sunak said arms licences were kept under careful review according to “regulations and procedures that we’ll always follow”.