Keir Starmer has said he felt "proud to be British" on Saturday, when Britain united in a show of support for Ukrainian President Volodymyr Zelenskyy after his bruising showdown with Donald Trump.
Speaking in the House of Commons this afternoon, Sir Keir welcomed the cross-party support he received from the Conservatives and Liberal Democrats, injecting a moment of patriotism into the serious parliamentary debate.
Responding to a series of supportive questions from Tory leader Kemi Badenoch, Sir Keir replied: "Can I thank the leader of the opposition for her support for the measures we are taking."
"It matters across this house that we are united on this issue. It matters to the Ukrainians and to President Zelenskyy.
"I can tell you he was moved by the reception he got in our country on Saturday. And I can tell you I felt very proud to be British on Saturday when our country spoke with one voice."
The comment came after the Prime Minister had delivered a crucial update to MPs following Sunday's major London summit of European leaders.
Sir Keir said that the hundreds-strong crowd of supporters outside the gates of Downing Street who cheered President Zelenskyy's arrival in London "spoke for the whole country".
While he said that the Oval Office scenes between the Ukrainian and US presidents were "something no on in this house ever wanted to see", he insisted Donald Trump remains steadfastly committed to a peace deal.
The PM argued: "I welcome the understanding from our dialogue that our two nations will work together on security arrangements for a lasting peace in Ukraine."
"I also welcome the President's continued commitment to that peace, which nobody in this house should doubt for a second is sincere."
Following the summit with fellow leaders on Sunday, Sir Keir said there are now four principles behind the actions Europe will take to achieve peace in Eastern Europe.
He said Britain will play in a leading role in any such military coalition, with "boots on the ground and planes in the air."
However the Prime Minister continued to argue that any military role for Europe "must have strong US backing", something Donald Trump is yet to guarantee.
Nigel Farage was met by groans from MPs when he rose in the Chamber to congratulate Keir Starmer - "a Remainer Prime Minister" - on using Brexit freedoms effectively on Sunday.
The Reform UK leader argued Britain is now in a "unique position" compared to the rest of Europe and described yesterday as a "triumph".
Mr Farage said: "I also applaud him making such positive words about President Trump and our relationship with America, even if nobody behind him agrees."
"Here's the key: President Zelenskyy has now accepted he's going to sign the minerals agreement with America, and America's going to put in $100bn or whatever it is and thousands of Americans will be in ."
Mr Farage asked whether the position of US workers involved in Ukrainian mineral extraction will be enough of a security guarantee or whether Britain will need to send troops to maintain peace.
The Prime Minister argued that the mineral deal is not enough on its own, but hit back at Mr Farage that " is the aggressor, Zelenskyy is a war leader whose country has been invaded, and we should all be supporting him and not fawning over Putin."