The contest for London mayor will pit a former Labour government minister against a wealthy Conservative environmentalist.

The Conservatives said Friday that party members had chosen Zac Goldsmith in an online primary to fight the May 5 election against Labour's Sadiq Khan.

Goldsmith is a lawmaker and former editor of The Ecologist magazine from a prominent wealthy family. He said transit, housing and the environment would be his top priorities if he's elected.

Khan, son of a bus driver from Pakistan, is a lawmaker who served in Prime Minister Gordon Brown's government.

London has had two elected mayors since the post was created in 2000, both larger-than-life personalities. Labour left-winger Ken Livingstone ran the city from 2000 to 2008, and tousle-haired Conservative Boris Johnson has been in charge since then.