(Reuters) Sadiq Khan of Britain’s opposition Labour Party was sworn in as Mayor of London on Saturday, becoming the first Muslim to head a major European capital after an election campaign marked by the ruling Conservatives’ efforts to link him to extremism.The son of a Pakistani immigrant bus driver and a seamstress, Khan defeated Conservative candidate Zac Goldsmith, the son of a billionaire financier, by a record margin to secure the biggest individual mandate in British political history.

The Financial Times said the result highlighted London’s tolerance, a “remarkable triumph over the racial and religious tensions that have bedevilled other European capitals”.

“My name is Sadiq Khan and I’m the Mayor of London,” the 45-year-old said to wild applause at the ceremony at Southwark Cathedral attended by the city’s police chief, politicians and leaders of different faiths.

Khan’s election also puts a supporter of Britain remaining in the European Union at the helm of the global financial centre, even though the issue barely came up in the campaign.

Goldsmith and outgoing mayor Boris Johnson favour a vote to leave when Britain holds a referendum on the issue next month.

Politicians from all sides lined up to condemn the Conservative Party tactics in the race, but in the aftermath, Defence Secretary Michael Fallon refused to apologise.

“In the rough and tumble of elections, you get stuff said, questions asked,” Fallon told the BBC. “I think it is right that candidates for some of the most important offices in Britain do get scrutinised about their past associations.”

Conservatives including Prime Minister David Cameron and Fallon himself had questioned whether London would be safe under the control of Khan, a former human rights lawyer who grew up in public housing in the capital’s inner city.

“They used fear and innuendo to try to turn different ethnic and religious groups against each other – something straight out of the Donald Trump playbook,” Khan told the Observer newspaper.

Many commentators said the focus on religion had backfired in a city noted for its diversity.

During the race