Mr Khan arrived at City Hall to be greeted by a crowd of wellwishers, following his victory in last week's election.

He received a total of 1,310,143 votes - 57% of the total - compared to Conservative Zac Goldsmith's 994,614, after the capital had its largest ever turnout at 45.6%.

Mr Khan's victory ends eight years of Conservative leadership at City Hall, under Boris Johnson.

Labour's former Shadow Home Secretary Yvette Cooper has highlighted Mr Khan's success as an example of the sort of tactics the party needs to adopt if it is to succeed at the ballot box.

The new Mayor was widely seen to have distanced himself from party leader Jeremy Corbyn's left-wing agenda.

Ms Cooper, who lost out in last year's leadership contest, said Mr Corbyn must urgently develop a strategy to win back votes across Britain.

She told the BBC Radio 4 Today programme: "We don't know what is going on in the Tory Party, at what point they will change leaders.

"Therefore we need a plan and a strategy to win votes across the country, because we need a Labour government."

Jeremy Corbyn is expected to address Labour MPs after being warned by Mr Khan that he must appeal to voters beyond the party's core support.

The new London Mayor used a series of media appearances over the weekend to issue a warning about the party's direction.

Mr Corbyn was a notable absentee from his signing-in ceremony, but the two men are expected to hold talks today.