Sir Sadiq Khan has been told by the Labour Government that “a period of silence would be most welcome” in a public rebuke over his warnings of “resurgent fascism” under a new Donald Trump presidency.

The warning to the mayor of London came as the Republican tycoon returned to the White House as the 47th US president.

Writing for The Observer on Sunday, Sir Sadiq highlighted the AfD party in Germany, National Rally in France and Mr Trump in the US and branded them “opportunists who seek to divide people for personal and political gain”.

He added: “We should be in no doubt, this is a perilous moment. The spectre of a resurgent fascism haunts the west.”

Sir Keir Starmer’s administration has moved to build bridges with Mr Trump after senior Labour figures including Foreign Secretary David Lammy were previously strongly critical of him, and following a row over party activists campaigning for Mr Trump’s defeated presidential opponent Kamala Harris.

The Government was pressed over Sir Sadiq’s comments during a question in Parliament.

House Of Cards author and Tory peer Lord Dobbs said: “I wish the Government well in its attempts to get a free trade deal with the United States, but surely isn’t it time for a little bit of joined-up thinking?

“While the Prime Minister himself says this is what he wants, the Labour mayor of London insists on calling, over the weekend, President Trump essentially a fascist and that we are on the road to the 1930s.

“This isn’t a special relationship, they are turning it into a sack of ferrets.

“Does the Government agree with the Labour mayor of London or will it repudiate the comments he made over the weekend?”

Responding, Lord Leong, who as a Lords whip holds the same constitutional position as a minister, said: “I disagree with the mayor of London.

“President Trump won the election… and he has a mandate and we have to work with him.

“Sometimes I would say a period of silence would be most welcome.”

After his remarks in The Observer, Sir Sadiq struck a more conciliatory tone, telling BBC London he “wanted to work closely with the American president”, with whom he has previously had a tetchy relationship.

But in a further dig, the mayor expressed his hope that Mr Trump will be “different from the last time he was president”.