His decision to run for the London Mayoral election of 2000 against the official Labour Party candidate,
Frank Dobson, contravened Labour Party rules and his membership of the party was terminated. He had to run as an independent. On 5 May 2000, he was elected Mayor of London. His campaign for Mayor was supported by celebrities such as actors
Neil Pearson and
Harry Enfield and the pop singer
Damon Albarn.