Sir Keir Starmer’s pledge to recognise a Palestinian state could break international law, an influential group of peers has warned. Some 38 members of the House of Lords, including some of the UK’s most eminent lawyers, have written to Attorney General Lord Hermer about the Prime Minister’s announcement.

As first reported by the Times newspaper, the peers warned that Sir Keir’s pledge to recognise Palestine may breach international law as the territory may not meet the criteria for statehood under the Montevideo Convention, a treaty signed in 1933. On Tuesday, Sir Keir announced the UK could take the step of recognising statehood in September, ahead of a major UN gathering.

The UK will only refrain from doing so if Israel allows more aid into Gaza, stops annexing land in the West Bank, agrees to a ceasefire, and signs up to a long-term peace process over the next two months. However Israel is extremely unlikely to do anything like this as long as Hamas refuses to release hostages it seized on October 7 2023, and critics say Sir Keir has given the terror group an incentive to refuse to make peace.

The Prime Minister also said Hamas must immediately release all remaining Israeli hostages, sign up to a ceasefire, disarm and “accept that they will play no part in the government of Gaza”, but he will recognise Palestine as a state whether they do so or not.

In their letter to Lord Hermer, the peers said Palestine “does not meet the international law criteria for recognition of a state, namely, defined territory, a permanent population, an effective government and the capacity to enter into relations with other states”.

There is no certainty over the borders of Palestine they said, and no single government, as Hamas and Fatah are enemies.

Lord Hermer has previously insisted that a commitment to international law “goes absolutely to the heart” of the Government’s approach to foreign policy.

In their letter seen by the PA news agency, the peers added: “You have said that a selective, ‘pick and mix’ approach to international law will lead to its disintegration, and that the criteria set out in international law should not be manipulated for reasons of political expedience.

“Accordingly, we expect you to demonstrate this commitment by explaining to the public and to the Government that recognition of Palestine would be contrary to the principles governing recognition of states in international law.”

Among the respected lawyers to have signed the letter are Lord Pannick – who represented the previous government at the Supreme Court over its Rwanda scheme – as well as KCs Lord Verdirame and Lord Faulks.

Some of Parliament’s most prominent Jewish voices, including crossbench peer Baroness Deech, Labour’s Lord Winston and the Conservatives’ Baroness Altmann, have also put their name to the letter.

Former Conservative cabinet ministers Lord Pickles and Lord Lansley have also supported it, as has Sir Michael Ellis KC, a former Conservative attorney general and the only non-peer whose name appears on the letter as seen by PA.

The peers’ intervention follows condemnation of Sir Keir’s announcement by Emily Damari, a British-Israeli women who was held captive by Hamas for more than a year.

The PM is “not standing on the right side of history” after his pledge to recognise a Palestinian state, she said.

Israeli Prime Minister Benjamin Netanyahu meanwhile claimed it “rewards Hamas’s monstrous terrorism”.

But ministers have insisted the step is important and is not an example of gesture politics.

“This is about the Palestinian people. It’s about getting aid in to those starving children,” Transport Secretary Heidi Alexander said on Wednesday morning.

Asked directly whether the release of hostages by Hamas is an explicit condition of Palestinian recognition, Ms Alexander told BBC Radio 4: “We will be making an assessment in September and we expect Hamas to act in the same way as we expect Israel to act.”

She later added: “We’re giving Israel eight weeks to act. If they want to be sat at the table to shape that enduring peace in the region, they must act.”

Sir Keir had been coming under pressure from MPs to recognise statehood, and last week more than 250 cross-party members signed a letter calling on him to act.

Elsewhere on Wednesday, Palestine Action’s co-founder won a bid to bring a High Court challenge over the group’s ban as a terror organisation.

Huda Ammori is challenging Home Secretary Yvette Cooper’s decision to proscribe the group under anti-terror laws, announced after the group claimed responsibility for action in which two Voyager planes were damaged at RAF Brize Norton on June 20.