Three former Supreme Court judges have joined more than 600 legal experts in asking the UK government to ban weapons sales to Israel. The 17-page letter comes after seven aid workers were killed in an Israeli airstrike on Monday.

The judges warned in the letter that shipments must halt because the UK risked breaking international law over a “plausible risk of genocide” in Gaza.

Rishi Sunak is already facing significant cross-party pressure, and on Tuesday, he declared the UK had a “very careful” arms licensing procedure.

British sales are fewer than those of other countries, like Germany and Italy, and are overshadowed by the billions given by its major arms supplier, the United States.

In the last hour, Israel’s military spokesman has announced that “in accordance with the assessment of the situation,” it has halted leave for all combat troops.

Posting on social media, the Israel Defense Forces (IDF) states: “The IDF is at war, and the issue of the deployment of forces is constantly reviewed according to need.” The administration is coming under rising cross-party pressure to suspend arms supplies to Israel.

Britain does not sell a significant amount of weaponry or ammunition to Israel. The Campaign Against the Arms Trade states that since 2008, the UK has issued arms export licenses to Israel valued at only a little more than 500 million pounds.

Lord Ricketts, a former national security adviser, told the BBC that the UK should cease military shipments to Israel. Sir Alan Duncan, the former Conservative foreign minister, also warned that Israel was breaching international humanitarian law and that ongoing UK weaponry shipments could not be justified.

David Lammy, the Shadow Foreign Secretary, said the government should publish its latest legal opinion regarding whether Israel was complying with international humanitarian law. And if there was a clear risk of a breach, then arms sales should be banned.

The Lib Dem leader, Sir Ed Davey, believes the government should take “swift action” to cease exports now, while the SNP said parliament should be summoned so MPs may vote on ending arms sales to Israel. But a senior government source told the BBC that an arms embargo on Israel was “not going to happen.”.