Foreign Secretary David Lammy has said he hopes the UK’s move to recognise a Palestinian state in September will “affect the situation on the ground” and lead to a ceasefire in Gaza.

On Tuesday Prime Minister Sir Keir Starmer announced the UK would take the step unless Israel met certain conditions including agreeing a ceasefire and reviving the prospect of a two-state solution.

Israeli Prime Minister Benjamin Netanyahu reacted furiously, saying the decision rewarded “Hamas’ monstrous terrorism”.

Emily Damari – a British-Israeli who was held hostage by Hamas in Gaza for 15 months – said the move was a “moral failure” which “sends a dangerous message: that violence earns legitimacy”.

Her comments echoed a statement from lawyers for 10 hostages held by Hamas who are either British or have close ties to the UK.

They said they feared the UK’s announcement would remove the incentive for Hamas to agree a ceasefire and release the remaining hostages because it could make recognition of a Palestinian state “less likely”.

Speaking at the UN in New York, Lammy said the world had seen “the most horrific scenes” in Gaza and the time had come to “abate the suffering of the Palestinian people”.

Tuesday’s announcement “puts us on a pathway towards recognition”, he told the BBC’s Tom Bateman.

“It is my sincere hope that the decision that we have taken today affects the situation on the ground, and we get to that ceasefire, we get to those hostages coming out as soon as possible,” he said.

Lammy added that the global community was “deeply offended by children being shot and killed as they reach out for aid” and called for the flow of medical equipment and supplies to be restored.

Netanyahu criticised the UK’s announcement, writing on social media: “A jihadist state on Israel’s border TODAY will threaten Britain TOMORROW”.

“Appeasement towards jihadist terrorists always fails. It will fail you too. It will not happen.”

Until now, Starmer’s government has said recognition of a Palestinian state should come as part of a long-term political solution to the conflict in the Middle East, without specifying the exact stage.

But Sir Keir has been facing mounting pressure, both internationally and domestically, to announce recognition now as a means to exert pressure on Israel.

President Emmanuel Macron France announced on Friday that France would recognise a Palestinian state in September, joining Ireland, Spain and Norway, who took the step last year.

A public letter calling for immediate recognition had been signed by 255 MPs, including more than half of Labour MPs, by Monday.

In a statement on Tuesday evening, Sir Keir said the UK would make the move in September unless Israel agreed to a ceasefire, ruled out annexing the West Bank, and “revived” the prospect of a two-state solution to the conflict.

He also said Israel should also take “substantive steps to end the appalling situation in Gaza,” amid warnings amid warnings from aid agencies of mass starvation in the territory.

He added that Hamas, a proscribed terror group in the UK, must immediately release all hostages, sign up to a ceasefire, disarm, and “accept that they will play no part in the government of Gaza”.

“We will make an assessment in September on how far the parties have met these steps,” he added.

Labour MP Sarah Champion, who coordinated the letter calling for recognition, said she was “delighted and relieved” at the announcement.

But she added she was “troubled our recognition appears conditional on Israel’s actions,” adding “recognition is about the self-determination of the Palestinian people”.

Liberal Democrat leader Sir Ed Davey said recognition “should have taken place many months ago” and should not be used as “a bargaining chip”.

However, both the Conservatives and Reform UK have argued now is not the right time for the UK to recognise Palestine.

Conservative leader Kemi Badenoch labelled the move “political posturing at its very worst” and claimed Sir Keir was merely acting to quell dissent in the Labour party.

Reform UK’s Zia Yusuf told the BBC’s Newsnight programme that the prime minister had made a “political calculation” that “trivialised” the situation in Gaza.

The Israeli military launched a campaign in Gaza in response to the Hamas-led attack on southern Israel on 7 October 2023, in which about 1,200 people were killed and 251 others were taken hostage.

At least 60,034 people have been killed in Gaza since then, according to the territory’s health ministry.