Sadiq Khan fears change to voting system could bring London Tory mayor

Labour mayor urges Lib Dem and Green supporters to lend him their votes' in May's first-past-the-post election

Sadiq Khan has called on Liberal Democrat and Green supporters to lend him their votes" in the May mayoral election, saying changes in the voting system mean he could lose to the Conservatives' Susan Hall.

This year's election on 2 May will be held under the first-past-the-post system, meaning voters will only get one vote each. In previous contests, Londoners have been able to have a first and second preference.