David Cameron, the former foreign secretary, sat on advice from Foreign Office officials in Israel and London that there was clear evidence of breaches of international humanitarian law in Gaza for which the UK risked being complicit, a former Foreign Commonwealth and Development Office (FCDO) adviser said.
The source, who contributed to the drafting of the advice, was speaking after the Labour government banned 30 of around 350 arms export licences due to a clear risk cited in a government memorandum published on Monday that they might be used in serious breaches of international humanitarian law.
The source said what has emerged in the memorandum “is similar to what was being sent to the government from at least February onwards in various drafts by Foreign Office advisers, much of it linked to the deteriorating humanitarian position in Gaza. But what has been eventually published is in much less strident language.
“The tragedy has to be considered: how many lives might have been saved if the arms export licences had been stopped then and not in September, and what the potential ripple effect might have been on how other countries would have reacted in ceasing trade.”
The source added: “The advice being sent through to the Foreign Office was clear that the breaches of IHL by Israel as the occupying power were so obvious that there was a danger of UK complicity if the licences were not withdrawn.”
A member of the previous government said its legal advice was in some respects similar to that published by Labour concerning the treatment of detainees and humanitarian aid, but insisted the legal advice was iterative and changing, adding it never said explicitly that ministers needed to suspend arms sales to avoid breaching international humanitarian law.
The inquest into how it took a British government 10 months to conclude a risk of serious breaches of IHL existed came as the Israeli prime minister, Benjamin Netanyahu, mounted a fierce rhetorical broadside against Labour for letting down Israel.
After other Israeli ministers had expressed disappointment at the British decision, Netanyahu went further saying on X: “This shameful decision will not change Israel’s determination to defeat Hamas, a genocidal terrorist organization that savagely murdered 1,200 people on October 7, including 14 British citizens.”
He added: “Just as Britain’s heroic stand against the Nazis is seen today as having been vital in defending our common civilization, so too will history judge Israel’s stand against Hamas and Iran’s axis of terror … With or without British arms, Israel will win this war and secure our common future.”
Israel is angry at the alleged insensitivity of the announcement’s timing, coming only 24 hours after it emerged that Hamas had killed six Israeli hostages. Ministers said the decision was announced on the first day MPs returned from summer recess.
The condemnation by Netanyahu came a day after a press conference during which he doubled down on his commitment to eradicate Hamas, but did not mention the UK arms ban. The broadside appears to be part of a wider strategy to rally Israelis behind his hardline negotiating strategy and against criticism from the wider world.
Israeli sources admit relations with the UK are increasingly strained, but at present they do not predict Netanyahu taking practical reprisals against the UK.
All UK components for the F-35 fighter jet programme would be almost entirely excluded from the ban, which is seen as a significant loophole by pro-Palestinian groups. By keeping British components to the F-35s out of the embargo, the UK hopes to minimise anger in Washington.
Across the wider middle east, the Jordanian foreign minister, Ayman Safadi, praised the British decision but called for a wider boycott. The UK prime minister, Keir Starmer, also conferred by phone with Mohammed bin Zayed al-Nahyan, the influential president of the United Arab Emirates. After signing the 2020 Abraham Accords, the UAE became an unofficial restraint on Israel annexing the West Bank, and is critical to establishing any post-Hamas Palestinian administration in Gaza.
The FCDO source said wider lessons needed to be drawn from the internal handling of the issue. The source said: “Israel highlights vital lessons globally for arms companies and countries which grant export licences as part of elaborate trade deals. The reality is that none of these licences are granted in isolation of other business and political interests, and are enmeshed with other forms of trade technology exchanges and security equity.
“Companies also bear a responsibility to respect international humanitarian and criminal law, as do governments.
“Internally, the Foreign Office does not seem very cohesive, with disputes between humanitarian, legal and political teams, as well as with sections of the ministry of defence.”
The critique came as a hearing in a long-running case claiming the Foreign Office had acted irrationally in refusing to ban arms sales was deferred on Tuesday by a high court judge for more than a month, to give the claimants time to reassemble its case in light of the Monday suspension of 30 of the 350 extant arms licences. The first full-day hearing is set for 18 November.
The campaigners from Al-Haq and the Global Legal Action Network said the UK has acted unlawfully in excluding from the sales ban almost all British components of the US-led F-35 jet fighter aircraft. The case is also likely to focus on the failure of the UK to reach an assessment on the legality of air strikes, sniper attacks and controlled demolitions in Gaza, as well as the exclusion of evidence of breaches of humanitarian law on the West Bank.