Brexit nemesis Michel Barnier has led French efforts to woo Sir Keir Starmer into closer ties with France and the EU.
Mr Barner, France’s Prime Minister, said he was “very happy” to see the Labour leader in Paris.
And he said Anglo-French relations will “be invaluable in facing the challenges that lie ahead”.
Sir Keir has made closer ties with the EU one of his top foreign policy goals.
But he is coming under pressure to review this amid fears President Donald Trump is planning to introduce punishing trade tariffs, which could severely hit the bloc.
Brexiteers want the Prime Minister to utilise the advantages of Brexit to forge a close relationship with the White House and avoid tariffs of up to 20 per cent.
Mr Barnier said: “Very happy to see you again, Keir Starmer, in Paris this morning.
“Franco-British friendship has a long history and has known trials. It will be invaluable in facing the challenges that lie ahead.
“Thank you, Mr. Prime Minister, for being with the French people on this November 11.”
The Prime Minister was personally invited to Paris by Emmanuel Macron and the two leaders were expected to discuss the war in Ukraine and the crisis in the Middle East.
But it is also the latest example of the two nations forging closer ties in the wake of the General Election, prompting fears the UK could be sucked back into the EU’s orbit.
Sir Keir and the French president laid a wreath at the Tomb of the Unknown Soldier at the Arc de Triomphe in the French capital, on the 106th anniversary of Armistice Day.
Sir Keir is the first UK prime minister to have attended the Paris commemorations since Churchill joined General Charles de Gaulle in 1944.
Known in France as Monsieur Brexit, Mr Barnier became France’s oldest prime minister since the Fifth Republic came into being in 1958.
Sir Keir’s biographer, Tom Baldwin, revealed in his book on the new Prime Minister that Mr Barnier was a fan of the Labour leader – and had even tipped him to move into Downing Street one day.
He wrote in Keir Starmer: The Biography: “Despite this veteran French politician spending most of his trying to agree a deal with the Conservative government, he also held talks with the Labour Party, writing in his diary in 2018 that Starmer was without doubt the figure in Labour’s hierarchy ‘who impresses me the most of his ability to grasp in detail what is at stake in the Brexit negotiations.
“He added ‘listening to him, I get the feeling that Keir Starmer will one day be Prime Minister.
“Starmer is clever, says Barnier. ‘What I saw over those years was how he was always learning.
“He improved, day after day, year after year. At the beginning he was wise enough to stay close to Corbyn and, while everyone else made mistakes, he was careful.
“From the first time we met I thought there was something about him.”
Sandro Gozi, the new chair of the European delegation to the EU-UK Parliamentary Assembly, is also today urging Sir Keir to cosy up to the bloc.
Mr Gozi told The Independent that issue of security and defence in Europe is “even more compelling” since Donald Trump won the race to the White House.
He added: “We know that we have a clear common interest in working together more and better on our security. I hope the election of Mr Trump will boost the cooperation between the UK on the security and military dimension.”
“I don’t see why we have a technology dialogue with the US and with India but we don’t have a dialogue with UK,” Mr Gozi said. “These could be new areas of cooperation in the common interest.”
