LONDON — During the height of the U.S. campaign, Britain’s former ambassador in Washington Kim Darroch revealed that Prime Minister Boris Johnson and his government were expecting — if not hoping — that President Trump would be reelected.

Before months of pandemic changed the math, Downing Street was imagining that four more years of Trump would smooth the way for a fast-track free-trade deal with the United States just when Johnson needed it the most, as Britain exits the European Union at year’s end.

But the win by former vice president Joe Biden has charged the “special relationship” between the two leaders and two closely allied countries with what the British might call a certain . . . awkwardness.

Johnson and President-elect Biden have never met, and though the British prime minister sent his congratulations, the message was somewhat bungled. In the official tweet from Johnson’s office, there were faintly visible words in the text, a ghost of an earlier, edited message, that congratulated Trump instead.

The goof was first spotted by the Guido Fawkes blog in Britain. The prime minister’s press office described it as “technical error,” explaining the government had prepared two different statements because the election was so close.

Biden, for his part, called Johnson last year the “physical and emotional clone of Donald Trump” in private remarks widely reported in British press.

Johnson could use a few friends these days. His aides are warring; England is in lockdown again; Britain continues to tally the highest death toll from the coronavirus in Europe. And the British prime minister still hasn’t secured a post-Brexit trade deal with the European Union.

But with Trump’s defeat, there’s no longer any reason for the Europeans to fear that Britain will get a quicker, better deal with the Americans. No longer can Johnson threaten Brussels negotiators — or calm his fellow Tories — with the feint: Okay, so long, mes amis, we will do better with the Yanks.

Johnson is the chief cheerleader for Brexit. His legacy will be forever tied to the departure. Biden, however, has made no secret he thinks Britain’s exit from Europe isn’t a great idea, sharing the skepticism of his former boss, President Barack Obama, who traveled to London in April 2016 to give a speech urging Britain to remain in the European Union.

This week, Biden included Johnson in the first round of calls placed by the former vice president to Western leaders, including those of France, Germany and, it did not go unnoticed, Ireland.

In the call to Johnson, Biden stressed his support for the 1998 Good Friday Agreement in Ireland, which was brokered by President Bill Clinton and ended decades of sectarian bloodshed. Biden emphasized the importance of implementing Brexit in a way that supports the still ongoing peace process, British officials said. In its readout of the call, Downing Street did not mention Northern Ireland.

Biden has made a big deal of his Irish heritage. And alongside House Speaker Nancy Pelosi (D-Calif.), he has warned the British that there will be no U.S.-Britain trade deal if Brexit undercuts the free movement of people and goods in an Ireland where the old militarized land frontier between north and south has been removed, and the border today is invisible.

Candidate Biden warned that “any trade deal between the U.S. and U.K. must be contingent upon respect for the agreement and preventing the return of a hard border.”

Johnson has potentially upset that delicate balance with legislation to carry out his version of a Brexit, called the Internal Market Bill, which one of his own ministers called a violation of international law. In the event that Britain cannot strike a trade deal with the European Union, the bill would place a priority on the free flow of goods between Northern Ireland and Britain, which in turn could reintroduce border checks to the island — between the Republic of Ireland, a part of the European Union, and Northern Ireland, a part of Britain.

In their 20-minute telephone call, Biden and Johnson sought common ground, “promoting global health security; pursuing a sustainable economic recovery; combating climate change; strengthening democracy, and working together on issues such as the Western Balkans and Ukraine,” according to the Biden transition team.

But there is a question about how much Washington will need London in a post-Brexit world.

Before Brexit, U.S. administrations could count on Britain to serve as an ally and proxy in Europe. But in a speech Tuesday in the House of Lords, former British prime minister John Major warned that Johnson’s Brexit makes Britain less important.

“Suddenly, we are no longer an irreplaceable bridge between Europe and America. We are now less relevant to them both,” said Major, a member of Johnson’s Conservative Party.

“We are a top second-rank power, but over the next half-century, however well we perform, our small size and population makes it likely we will be passed by the growth of other, far larger countries,” Major said. “In recent decades, we have consoled ourselves that we ‘punch above our weight’ in international affairs. I think that was true — but that was then, and this is now.”

Simon Fraser, a former top official in Britain’s Foreign Office, called a Biden win “problematic for our government,” according to the Guardian newspaper. 

Fraser said, “This is a government that was born of the disruption of Brexit in 2016, just as Trumpism was a reflection of that. Trump supported Brexit. My understanding is the relationship between London and the Biden team is not that strong.”

Robin Niblett, director of Chatham House, a London think tank, said in an interview that it was unlikely there would be natural chemistry between Johnson and Biden. “Biden and Biden’s people in their professionalism and moderation are very different to Boris Johnson and his boosterism and almost nostalgic view of Britain’s place in the world, so it’s not a natural marriage,” he said.

Still, Niblett said that there was a sense that Biden’s administration “will treat Boris Johnson very well, providing you don’t cut across the Irish question.” But when the Biden White House looks to Europe, it will look to the European Union first, not Britain, Niblett said.

Tom Tugendhat, a Conservative Party lawmaker and chair of the foreign affairs select committee, dismissed the argument that Britain matters less to Americans now.

“I’ve heard it before, and I didn’t believe it then, and I don’t believe it now,” he said in an interview. “That has been a consistent line of people who believe in decline since 1945, and yet somehow it turns out that two countries that share a vision of the world, with an understanding of international outreach and willingness to act around the world, find themselves standing together rather often.”

British officials said the two countries will continue to work together — as they did through the Trump administration — on military, security and intelligence portfolios. In a Biden administration, the Brits see a role with the Americans on tackling climate change, defending Hong Kong democrats, curbing Russia and bolstering NATO.