London (AFP) – 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, broke from convention by taking his oath of office in a multi-faith ceremony at Southwark Cathedral.

Sir Ian McKellen bows down to Khan (Photo by John Stillwell – WPA Pool /Getty Images)

(YUI MOK/AFP/Getty Images)

LONDON, ENGLAND – MAY 07: Sadiq Khan attends an official signing ceremony at Southwark Cathedral 

Khan smiles for the camera (Photo by John Stillwell – WPA Pool /Getty Images)

Khan’s family in the front row. Tieless and hijab-wearing, one clutches a baseball cap (YUI MOK/AFP/Getty Images)

Britain’s incoming London Mayor Sadiq Khan (R) is greeted by Doreen Lawrence (YUI MOK/AFP/Getty Images)

Khan looks skyward (Yui Mok – WPA Pool /Getty Images)

Khan greets some children (YUI MOK/AFP/Getty Images)

“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.

(Yui Mok – WPA Pool /Getty Images)

In his victory speech in the early hours of Saturday morning, Khan had referenced the negative campaign against him by saying London had chosen “unity over division”.

(Yui Mok – WPA Pool /Getty Images)

Conservative Prime Minister David Cameron had led the attacks against Khan for sharing platforms with radical Muslims at public events, and Goldsmith said he was “radical and divisive”.

(Yui Mok – WPA Pool /Getty Images)

Former Labour leader Ed Miliband (left) with Metropolitan Police Commissioner Sir Bernard Hogan-Howe (Yui Mok – WPA Pool /Getty Images)