Khan's re-election and the re-election of Labour mayors in Manchester, Liverpool, Salford, and Bristol came after a bruising set of results for Labour in local elections in its former heartlands in central and northern England-known as the party's "Red Wall"-which followed a disastrous performance in the 2019 national vote".
Mayor of London Sadiq Khan speaks after being reelected in the London mayoral election, at the City Hall in London, Britain, May 8, 2021.
The race was tighter than opinion polls had suggested, but still amounted to a comfortable victory for Mr Khan, who had been leading throughout the campaign.
Conservative challenger Shaun Bailey had been effectively written off by some even within his own party in the run up to the 6 May election, but in results declared so far he has come out on top in areas previously won by the current mayor.
Although Khan failed to win an outright majority in the first round, he ultimately prevailed in the second round when second preference votes were counted.
London Mayoral election results since 2000
"There is no question we are seeing significant impact from turnout and voters believing they could put a smaller party first preference without influencing the election result".
In his victory speech from City Hall, Mr Khan said he was "deeply humbled" to be re-elected as mayor, and pledged to a build a "better and brighter future" for the capital following the coronavirus pandemic.
"It's in this spirit that I promise to lead London over the next three years, building bridges between the different communities in our city, building bridges across cultural, social, and class divides", he said.
He said he wanted "to ensure London can play its part in a national recovery" and to "build a brighter greener and more equal future" for the United Kingdom capital.
Khan, who became the first Muslim to head a major Western capital after his victory in 2016, won 55.2 percent of the vote compared with 44.8 percent for Shaun Bailey, the candidate from the ruling Conservative party.
Bailey, who is of British Jamaican heritage, said to the Pakistani heritage Khan: "I hope you take this opportunity to focus on the fact that people who look like me are four times as likely to be murdered than people who look like you".