Lord David Cameron has said he is “worried” Israel may have broken international law in Gaza.
The foreign secretary said he regularly consulted government lawyers over incidents in the war, but refused to say whether the legal advice suggested Israel had acted illegally.
Lord Cameron stressed the government had not changed its support for Israel.
Since the outbreak of war following Hamas’ attack on 7 October, over 23,000 Palestinians have been killed.
The Hamas-run health ministry says more than 59,000 Palestinians have been injured.
Israel declared war on Hamas after the group led a massive attack on communities inside Israel, killing about 1,200 people, mostly civilians, and taking some 240 others back to Gaza as hostages.
Israel is also fighting a claim from South Africa that it is committing “genocidal” acts in Gaza at the International Court of Justice.
Lord Cameron said he did not agree with South Africa’s claim.
Speaking during his first grilling by MPs since joining the House of Lords, the former prime minister said: “I don’t think that is helpful, I don’t agree with it, I don’t think it’s right”.
During a tense exchange with SNP MP Brendan O’Hara, Lord Cameron said he has seen things “deeply concerning” during the crisis but did not directly criticise the country’s actions.
He called on Israel to allow in more humanitarian aid and restore water supplies to northern Gaza.
But Lord Cameron repeatedly side-stepped questions on whether he had seen legal advice suggesting Israel had breached international law, telling the foreign affairs committee “I don’t want to answer that question”.
He said: “If you’re asking me am I worried that Israel has taken action that might be in breach of international law because this particular premises has been bombed or whatever?
“Yes, of course I’m worried about that, and that’s why I consult the Foreign Office lawyers when giving this advice on arms exports.”
But he hinted that government lawyers had not suggested international law had been broken. He told MPs the legal advice he had seen was “consistent with the fact we have not changed” rules on exporting weapons to Israel.
Tory MP Bob Seely put it to Lord Cameron that he had seen legal advice suggesting the Israeli government is “vulnerable to a challenge from the Hague court and from elsewhere that in some of the things they are doing in, potentially, in relation to proportionality, there is a vulnerability.”
“It’s close to that,” Lord Cameron replied.
Action in Israel
Downing Street later said Israel needs to “act carefully” and avoid risking further escalation in its war with Hamas.
Asked if Rishi Sunak shares Lord Cameron’s concerns about whether Israel has been acting within international law, the prime minister’s official spokesman said: “It is an issue we continue to keep under review and obviously we have made our views clear to the Israeli government at a number of levels on this.”
The spokesman added: “Fundamentally, though, we recognise that it is Israel that is responding to a terror attack, first and foremost.”
Two British nationals are still being held hostage by Hamas as heavy bombardment and fighting continues to shake the region, Lord Cameron told the committee.
Asked if he knew if the hostages are alive, Lord Cameron said: “I just don’t want to say any more. We don’t have any information to share with you.”
During a ceasefire in November, 105 hostages were released by Hamas.
Lord Cameron’s comments come as US secretary of state Antony Blinken held talks in Israel seeking to set a plan for Gaza’s post-war future.
Mr Blinken has called for winding down of the Israeli military campaign in Gaza to reduce regional tensions.
US officials have called for the Palestinian Authority, which governs parts of the Israeli-occupied West Bank, to take over in Gaza and for negotiations to resume on the creation of a Palestinian state.