The British government has accepted that Israel as an occupying power had a duty under international humanitarian law to provide basic supplies to the people of Gaza. The admission came when David Cameron, the foreign secretary, urged Israel to remove barriers on the delivery of humanitarian aid into the territory that were risking “real, widespread hunger”. Lord Cameron listed a series of changes Israel had to make including opening border crossings 24 hours a day and at weekends. On Tuesday, in his first cross-examination by MPs on the foreign affairs select committee since his surprise elevation as foreign secretary, Cameron came under intense scrutiny over whether Israel’s military siege of Gaza was in breach of international humanitarian law. At first he said he was unsure if Israel was legally the occupying power in Gaza, but accepted de facto that was the case. Challenged about whether Israel had a legal duty as the occupying power to supply water to Gaza, Cameron conceded Israel ought not to have turned supplies off, and should restore water. The committee chair, Alicia Kearns, then pressed Sir Philip Barton, the permanent under secretary at the Foreign, Commonwealth and Development Office, to admit Israel as the occupying power had an obligation under international humanitarian law to supply water. Sir Philip first said: “You ask me a technical question about occupying powers and what their obligations are in international law. I imagine you are correct, chair, but I am not a lawyer.” Kearns interrupted: “We have come to such a good place working with you because we have confidence that you do know these details. You know it is not that ‘I presume you are correct.’ That is the duty on an occupying power.” Sir Philip replied: “I think that is right. So yes.” Cameron said he had been given no advice that he should propose that UK arms export licences to Israel be stopped, and tried to avoid answering whether he had been given legal advice that some of Israel’s actions were in breach of international humanitarian law, saying: “On lots of occasions that has come under question.” He added that he was worried Israel had taken action that might be in breach of international law, but that was why he consulted his department’s lawyers. He had not sought nor did he expect Israel would provide details of its targeting methods but said he had been given figures by Israel of its collateral damage percentage. He said: “We know what they say is not good enough.” Kearns said she believed it to be 20%. The foreign secretary also rejected the separate claim by South Africa that Israel is committing a genocide, an assertion due to be tested at the international court of justice in The Hague on Thursday. “I don’t think it is helpful. I don’t agree with it. I don’t think it is right. I don’t think we should bandy around terms like genocide,”he said. Although Cameron stressed it was for the courts to define genocide not states, he added: “Our view is that Israel has a right to defend itself.” The foreign secretary was at his most critical of Israel in describing the blockages to aid reaching Gaza, saying: “We’re at about 150 trucks a day getting into Gaza, we need to be closer to 500. Every day that we’re not closer to 500, we’re going to have more people going hungry, we’re going to have more people getting disease, there is a danger of there being real widespread hunger. At the moment something like 90% of Gazans are getting less than one meal a day.” He said he had set out a series of changes that only Israel could make to end the blockages, including ensuring the Kerem Shalom crossing from Jordan into Gaza was open seven days a week, ensuring the Nitzana checking point, south-east of the Rafa crossing, was open 24 hours a day, and giving the aid convoys that were arriving through Jordan unhindered access into Gaza. He added: “Crucially, none of these things will work unless inside Gaza, you actually have UN personnel, trucks and fuel capable of taking the aid around Gaza. And again, only the Israelis can really fix that because there’s a bunch of visa applications that are outstanding for people to be there. There’s a need for armoured cars for the aid to be distributed and taken around with. And that needs to be fixed and needs to be fixed urgently.” Cameron admitted Israeli politics had moved in a completely different direction since his time as prime minister so now “it was hard to find anyone that supports a two-state solution. But hopefully out of this crisis we can try to start again to make the long-term argument that the only way to get peace and security is through a two-state solution. But it will be a hard ask.” More broadly he said the Ukraine war was a generational challenge and it was necessary to prove to Vladimir Putin that he could not win through a waiting game, adding that the west had to be ready to support Ukraine through 2024, 2025 and 2026.