Sir Keir Starmer has said he will work with Donald Trump if both men are in power later this year after the former president’s hush money conviction.
The Labour leader described Mr Trump’s guilty verdict as an "unprecedented situation", but promised to “work with whoever is elected president”.
“That’s what you’d expect,” he added.
A New York jury found Mr Trump guilty of 34 charges relating to the falsification of business records in a scheme to illegally influence the 2016 election through hush money payments to adult film actress Stormy Daniels, who said the two had sex.
Mr Trump intends to appeal the convictions.
The conviction makes him the first criminally convicted US president in history.
Rishi Sunak refused to comment on the ex-president’s conviction when asked by reporters.
But at a campaign event in Inverclyde on Friday, Sir Keir said: "We have a special relationship with the US that transcends whoever the president is, but it is an unprecedented situation. There is no doubt about that.
"And there’s a long way yet to go I think in relation to what happens next."
The relationship between Mr Trump and Sir Keir could be awkward given the pair’s personal and political differences.
Labour’s shadow foreign secretary, David Lammy, previously described Mr Trump as a “racist KKK and Nazi sympathiser”.
Mr Lammy has recently been praised for his international diplomacy, however, having made attempts to build relationships in the Trump camp.
Asked today whether he would work with a convicted felon in the White House if both men are re-elected, Mr Sunak said: “You wouldn’t expect me to comment on another country’s domestic politics or judicial processes.
"I’m focused squarely on the election here at home, talking to people across the country about the choice at our election.
"That’s my focus."
His work and pensions secretary, Mel Stride, said however that while Mr Trump’s conviction was “extraordinary”, the relationship between the UK and US would continue whatever the results of America’s election in November.
Responding to his conviction, Mr Trump said the trial was rigged and a disgrace and said the “real verdict” would be delivered by voters in November, when the US presidential election takes place.
“We have a country that’s in big trouble, but this was a rigged decision right from day one, with a conflicted judge who should have never been allowed to try this case,” Mr Trump said.
He added: “I am a very innocent man.”
Several of Mr Sunak’s Conservative MPs have backed Mr Trump to return to the White House, including former minister Sir Jacob Rees-Mogg.
Sir Jacob said Mr Trump is “better disposed” towards the United Kingdom and that he would rather have the Republican candidate than President Biden.
Former prime minister Liz Truss claimed the “world was safer” when Mr Trump was in the White House.