On Sunday, Education Secretary Bridget Phillipson said the UK had “played a key role behind the scenes in shaping” the Gaza peace plan.
Britain had been involved in “complex matters of diplomacy”, she told Sky News, without providing further detail.
Appearing later on BBC One’s Sunday with Laura Kuenssberg, Phillipson was asked to spell out the UK’s role, and responded: “We do have a role, but of course the role of the US has been critical in this – we can all recognise that.”
However, Mike Huckabee, the US ambassador to Israel, called Phillipson’s comments “delusional”. Posting on X, he added: “She can thank [Trump] anytime just to set the record straight.”
Israel’s deputy foreign minister Sharren Haskel further criticised the UK’s claims on Sunday.
Also appearing on Sky News, she was asked whether the UK had played a key role, and said the “opposite” was true.
Haskel said decisions by the UK government – including the one last month to recognise Palestinian statehood – had “actually pushed Hamas to embolden their position”.
However, on Monday Trump’s Middle East envoy Steven Witkoff wrote on social media: “I would like to acknowledge the vital role of the United Kingdom in assisting and coordinating efforts that have led us to this historic day in Israel.
“In particular, I want to recognize the incredible input and tireless efforts of National Security Advisor Jonathan Powell.”
Monday’s summit in Egypt will involve a “signing ceremony” for the peace plan, “marking a historic turning point for the region after two years of conflict and bloodshed”, Downing Street said.
Sir Keir will thank Egypt, Qatar and Turkey for “bringing us to this point” as well as Trump, before calling for continued coordination to secure “swift progress towards phase two” of the truce.
No 10 added in its statement: “He will offer the UK’s steadfast support and engagement with international partners as we look to secure the ceasefire, get urgently needed humanitarian assistance into Gaza and secure a basis for a lasting peace and security.”
French President Emmanuel Macron will also attend, the Elysee Palace confirmed on Saturday, where he will “express his full support for the implementation of the agreement”.
Confirming the summit late on Saturday, a spokesperson for Egypt’s presidency said it was intended to “end the war in the Gaza Strip, strengthen peace and stability efforts in the Middle East, and open a new page in regional security and stability”.
Trump had told reporters at the White House on Friday that he would be travelling to the region on Monday, addressing Israel’s parliament the Knesset, before heading to Egypt.
He said: “We have a lot of leaders from all over the world coming too, they’ve been invited.”
Egypt’s foreign ministry had also said US Secretary of State Marco Rubio discussed arrangements for the summit with Foreign Minister Badr Abdelatty.
Shadow foreign secretary Dame Priti Patel said the prime minister’s visit to Egypt for the Sharm El-Sheikh summit would be a “photo opportunity” and the government has “had no role whatsoever” in the Gaza ceasefire.
“I think it’s extraordinary that Keir Starmer is apparently going to Egypt tomorrow when we’ve got plenty of domestic issues that he should be resolving,” she told Kuenssberg.
The ceasefire came into effect after the Israeli government approved the first phase of Trump’s ceasefire and hostage return deal on Thursday, following three days of indirect talks in Egypt.
The Israeli military said it had partially withdrawn troops from parts of Gaza and pulled back to an agreed position within the territory – though troops still occupy half of the Strip.
