Sadiq Khan was sworn in as London mayor Saturday after being elected the first Muslim leader of a major Western capital, as the Conservatives defended attempts to link him to extremism during the campaign.
The opposition Labour lawmaker, the son of a Pakistani bus driver who grew up in social housing in the city, broke from convention by taking his oath of office in a multi-faith ceremony at Southwark Cathedral.
"My name is Sadiq Khan and I'm the mayor of London," the 45-year-old said to cheers from supporters, who had earlier given him a standing ovation as he walked in.
He added: "I'm determined to lead the most transparent, engaged and accessible administration London has ever seen, and to represent every single community, and every single part of our city, as mayor for all Londoners."
Khan won 57 percent of the vote in Thursday's mayoral election, securing 1.3 million votes to see off multimillionaire Conservative Zac Goldsmith and make history as the city's first Muslim mayor.
In his victory speech in the early hours of Saturday morning, Khan referenced the negative campaign against him by saying London had chosen "unity over division".
Conservative Prime Minister David Cameron had led the attacks against Khan for sharing platforms with radical Muslims at public events.
There was criticism from across the political spectrum on Saturday at the tone of the Tory campaign, but Defence Secretary Michael Fallon insisted it was legitimate.
"Both candidates were asked questions about their backgrounds, their personalities, their judgment, the people they associate with," he told BBC radio.
"That's the nature of our democracy and the rough-and-tumble of politics."
- Clinton sends congratulations -
Hillary Clinton, the likely Democratic nominee for the US presidency, led international congratulations, tweeting: "Son of a Pakistani bus driver, champion of workers' rights and human rights, and now Mayor of London. Congrats, @SadiqKhan. -H"
New York Mayor Bill de Blasio said he was looking forward to working with his "fellow affordable-housing advocate" while Paris Mayor Anne Hidalgo tweeted that Khan's "humanity (and) progressivism will benefit Londoners".
In Pakistan, Bilawal Bhutto, leader of the opposition Pakistan People's Party and son of former prime minister Benazir Bhutto, and rival opposition leader Imran Khan also tweeted their congratulations.
Former Conservative government minister Sayeeda Warsi, herself a daughter of a Pakistani bus driver, hailed Khan's victory and condemned her party's attacks against him.
"Our appalling dog-whistle campaign lost us the election, our reputation and credibility on issues of race and religion," she said.
Khan admitted representing some "pretty unsavoury characters" during his previous job as a human rights lawyer but said their views were "abhorrent" and condemned the Conservatives' "desperate" attacks.
Goldsmith's sister Jemima, the ex-wife of Pakistani cricketer and politician Imran Khan, said her brother's campaign "did not reflect who I know him to be".
Cameron's former adviser, Steve Hilton, said Goldsmith had brought back the "nasty party label".
In the audience at Southwark Cathedral was Doreen Lawrence, an anti-racism campaigner whose teenage son Stephen was killed by a gang of white youths.
"I never imagined in my lifetime I could have a mayor of London from an ethnic minority," she said.
- Labour losses elsewhere -
Khan broke the eight-year hold of the Conservatives on City Hall and succeeds the charismatic Boris Johnson in a prestigious post that has responsibility for transport, housing, policing and promoting economic development.
His success is a boost for Labour leader Jeremy Corbyn, a veteran socialist who has been battling a row over anti-Semitism and growing criticism from the moderate wing of his party since his election in September.
But Labour fared less well in other elections held Thursday.
The party was beaten into third place in Scotland, once a Labour stronghold, as the Conservatives became the official opposition to the Scottish National Party (SNP), which won a third term in office.
Labour maintained control of the Welsh assembly and lost only a handful of local council seats in England.
But critics warned it should have done better against a government that has lost support over welfare reforms and is deeply divided ahead of the referendum on Britain's membership of the EU on June 23. afp