President Emmanuel Macron of France held talks with Britain’s opposition leader, Keir Starmer, on Tuesday, in a sign of the international status being bestowed on the man hoping to become the first center-left British politician to win a general election in almost two decades.
Two days after he attended a gathering of center-left leaders in Montreal, where he shook hands with Prime Minister Justin Trudeau of Canada, Mr. Starmer’s private visit to the Élysée Palace in Paris was a personal win — and one that underscored his cautious ambition to mend fences with the European Union after years of hostility over Brexit.
“It was my first opportunity to say how much I value the relationship between our two countries, particularly when it comes to prosperity and security,” Mr. Starmer said in a video statement after the meeting in France. “And how, if we are privileged enough to be elected into power, we intend to build on that relationship and make it even stronger than it is today.”
Yet the diplomatic initiative was a calculated risk for Mr. Starmer, the Labour Party leader, who faced accusations of “Brexit betrayal” in Britain’s right-leaning tabloid press after he said he would seek to improve the country’s trade agreement with the European Union in 2025 if he wins power.
Until recently, Mr. Starmer had been highly cautious about greater engagement with Brussels for fear of giving Britain’s governing Conservative Party the chance to argue that he wants to overturn the result of the 2016 Brexit referendum.
Although recent polls have suggested that a majority of people in the country now have a negative view of Brexit, in part given a cost-of-living crisis fueled by inflation rates higher than in the bloc, the topic has largely faded from public political discourse.
Prime Minister Rishi Sunak’s office on Monday played down the significance of Mr. Starmer’s meeting with Mr. Macron in Paris, saying that it was not uncommon for opposition leaders to meet with foreign leaders.
While there is truth to that point, leaders of large nations rarely devote time to seeing opposition politicians with little prospect of power. Mr. Starmer, a former chief prosecutor, leads a party that has held a large, consistent lead in opinion polls for most of the past year, and Mr. Sunak is required to call the next election by January 2025.
Mr. Macron kept Tuesday’s meeting behind closed doors to limit any embarrassment to Mr. Sunak, but the optics were good for the Labour leader.
“From Starmer’s point of view, he looks statesmanlike and he’s getting to be known — all of those are positives,” said Catherine Barnard, a Cambridge University professor who is an expert on Britain’s relations with the European Union.
Charles Grant, the director of the center for European Reform, a research institute, said Mr. Starmer knew that after years of tension over Brexit, an incoming Labour government’s credibility with the European Union could be quite low.
“So Starmer is seeing European leaders like Macron to try and prepare them, by letting them know in advance some of his plans for a Labour government, and to reassure them that it is going to be very different, that it’s not going to be Rishi Sunak Mark II,” he said.
Mr. Starmer told The Financial Times on Sunday that if Labour won the next election, he would seek to improve Britain’s Trade and Cooperation Agreement with the bloc, a pact that is scheduled for review in 2025.
He has repeatedly ruled out rejoining the European Union, or the bloc’s customs union, which establishes common tariffs among member countries, or its huge single market, a trading zone where goods, capital, services and people flow freely. And he has made clear that he would not accept freedom of movement for European workers into Britain — a key requirement of single-market membership.
But Professor Barnard said that Mr. Starmer’s aims for re-engaging with the European Union — which include striking an agreement to help British food exporters — could yield only modest help for Britain’s economy.
“Everything I hear is that the E.U. is fed up with British exceptionalism,” she said. “They got everything they wanted out of the Trade and Cooperation Agreement.”
Mr. Grant said that Labour needed “to start blurring the edges of their red lines, particularly on the single market,” and that it should try to offer the European Union more cooperation on issues like energy, fishing policy, defense and security, and rebuilding Ukraine.
Last week, the Labour leader visited Europol, the European Union’s law enforcement agency, in The Hague to discuss plans to thwart people-smuggling gangs that send asylum seekers on small boats to Britain. Mr. Starmer said he would treat people-smugglers like “terrorists” and would seek a European Union-wide returns agreement by which some people arriving would be returned to continental Europe. But Conservative politicians seized on the chance to warn that an incoming Labour government would have to accept a quota of asylum seekers in return.
That was a reminder that despite the shift in opinion polls, any political missteps by Labour could make it harder to win over crucial Brexit supporters in the north and the Midlands who delivered a landslide victory to the Conservatives in 2019.