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, who said Sir Keir is “not standing on the right side of history”.

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

Responding to fears the decision to recognise a Palestinian state does not align with the 1933 Montevideo Convention, business minister Gareth Thomas told Times Radio: “We haven’t signed up to the Montevideo Convention, but is there a clear population in in Palestine? Yes, there is in Gaza and the West Bank.

“We have made clear that we think you would recognise the state of Palestine, and that state of Palestine would be based on the 1967 borders.

“Of course, there would have to be land swaps and there would be a shared capital of Jerusalem. They are well-regarded international views.”

Thomas stressed the UK Government had “made clear that there needs to be reform to the Palestinian Authority, that Hamas can have no role in the future government of Gaza and Palestine more generally”.

Pointing to the 147 other countries that have already recognised a Palestinian state, he added that the prime minister “was in talks this week with a series of countries, including Canada, and Canada have overnight, as you will have seen, taken the decision to recognise Palestine in September”.

Canadian Prime Minister Mark Carney said his country plans to recognise a Palestinian state as part of the two-state solution – that is Israel and Palestine living side-by-side.

Carney said his decision was prompted by the “catastrophe” in Gaza, and because he feared the prospect of a Palestinian state was “receding before our eyes”.

The Palestinian Authority – which runs parts of the occupied West Bank – must commit to “much-needed reform” he said, and Hamas, which controlled Gaza, “can play no part”.

The UK has said it too would recognise a Palestinian state at a UN summit in September unless Israel committed to a ceasefire.

Sir Keir has said the UK will only refrain from recognition 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.

He 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”.