Sadiq Khan has a simple, striking message for Londoners: He'll be a mayor for people of all faiths and none. Khan celebrated his landslide election victory Saturday in a multi-denominational ceremony at an Anglican cathedral accompanied by London's police chief, Christian and Jewish leaders, and stars of stage and screen. They gave Khan a standing ovation as he pledged to be an approachable Everyman for his city of 8.2 million — including more than a million residents who, like him, happen to be Muslim. "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 a mayor for Londoners," said Khan, the son of Pakistani-born immigrants who became a civil rights lawyer and, in 2005, London's first Muslim member of Parliament. "So I wanted to do the signing-in ceremony here, in the very heart of our city, surrounded by Londoners of all backgrounds," he said in Southwark Cathedral, just a few miles (kilometers) north of the state housing project where he grew up in the London district of Tooting. Khan's Labour Party candidacy to lead London triumphed in the face of a Conservative campaign seeking to tar him as sympathetic to Islamic extremists. Supporters said Khan's own message — that a victory for him would show the world how tolerant and open Britain was — carried far more power. "To have a Muslim mayor seems preferable to me to any alternative regardless of the politics," said actor Sir Ian McKellen, who greeted Khan at the cathedral gates. "I hope it's an image that will go round the world as representing a new sort of England that's at peace with itself regardless of race and so on. That's the beauty of it." Leading Muslim activists in the Conservative Party expressed shame and anger over their own party's attacks on Khan, saying they had recklessly stoked racism and intolerance.