James Corden mocks Boris Johnson in his 'Saturday Night Live' debut

James Corden has poked fun at Boris Johnson by dressing up as him for a Saturday Night Live skit.

The Gavin and Stacey star made his debut on the US comedy show dressed up as Johnson, complete with a messy blond wig, for a topical sketch about his recent run-in with Donald Trump.

Read more: First look at Gavin and Stacey Christmas special

At the start of the sketch, a voiceover announced: “This week, during the Nato conference in London, foreign leaders were caught on a hot mic making fun of President Trump.

“This included Canadian prime minister Justin Trudeau, French president Emmanuel Macron and British prime minister Boris Johnson, who Trump had considered a friend.

“Some dismissed it as petty high school gossip, but you should have seen what happened in the Nato cafeteria.”

Joining Corden was Jimmy Fallon as Trudeau, Paul Rudd as Macron and of course Alec Baldwin in his usual role as Trump.

The segment painted Johnson as trying to get in with “cool guys” Trudeau and Macron, as they banished Trump to the “losers’ table” in the cafeteria.

Corden did his best impression of a guffawing laugh as he spat into his hands and rumpled his own hair, while snubbing Baldwin’s Trump.

Read more: James Corden reveals the struggle to book Kanye West for Carpool Karaoke

Johnson has dismissed claims that he made fun of Trump behind his back as “nonsense” after microphones appeared to pick up him gossiping about the US president with other world leaders.

Comedian and actor Corden has made no secret of his disdain for Johnson in the past, having told him during a 2014 Jonathan Ross interview that his reasons for not making bike helmets mandatory were “bulls***”.

Read more: James Corden extends Late Late Show contract through 2022

In a recent monologue about the Grenfell Tower tragedy on his US talk show The Late Late Show, Corden highlighted Johnson’s attitude to fire safety as mayor of London, noting that the Tory politician cut the fire service budget, closed 10 fire stations and removed 27 engines during his time in charge of the city – while emphasising that Johnson had “nothing to do with Grenfell”.

“I’m not saying we shouldn’t trust Boris to sort this out,” Corden said. “Maybe someone brave enough to rock that fringe is brave enough to face this problem head-on, but just in case he isn’t, on the off-chance that Boris Johnson doesn’t care enough about most disadvantaged people in Britain, where does that leave us?”

He also told his US audience during the show: “How do I explain Boris Johnson to someone who’s never seen him before. Basically, America elected Donald Trump as their president, and now Britain is saying, ‘hold my beer’.”