Nicky Gavron has been chosen as Labour's candidate for the London mayoral election.

The party's electoral college backed her over the other contenders, West Ham MP Tony Banks and former leader of Harrow Council Bob Shannon.

After leading in each section and in both rounds of counting, Gavron defeated Banks - securing 52.19 per cent of the vote.

Gavron praised the two defeated candidates for fighting a "very fair and very positive campaign".

Despite accusations that many of Tony Banks' election addresses had failed to reach key trade unions, Banks said "we can now move on".

"We can now draw a line under the unhappy events of the selection and the last mayoral election," said the defeated candidate.

Banks went on to warn the government that for devolution to be truly effective the mayor would have to be given "more powers and an independent revenue stream".

Gavron pledged that she would not be a "zone one mayor" and vowed to put 7000 extra police officers on the beat by the end of her first term.

She also pledged £100 million for Greater London bus services.

The electoral college system split the vote on a 50- 50 basis between party members and affiliates, with two rounds of voting needed to secure a majority for one of the candidates.

In the first round, Gavron got 23.09 per cent backing from members, followed by Banks' 22.87 per cent and Shannon's 4.03 per cent,

In the affiliates section Gavron again topped the poll, obtaining 23.19 per cent to Banks' 16.04 per cent and Shannon's 8.64 per cent.

The combined result meant that in the first round Gavron received 46.28 per cent, Banks achieved 38.91 per cent and Shannon was eliminated after gaining just 12.67 per cent.

In the second round, 24.82 per cent of party members backed Banks and 25.18 voted for Gavron.

The affiliates vote also favoured Gavron over Banks, at 27.01 per cent to 19.83 per cent.

The combined result of the second round meant that Banks gained a 44.65 per cent share of the vote, trailing behind Gavron who received 52.19 per cent.

Gavron is currently Ken Livingstone's deputy in the Greater London Authority, but now faces the task of unseating the mayor in 2004 in order to claim the top post.

She has indicated that she will not seek to personalise the election as a battle between Labour and Livingstone, having called for the mayor to be readmitted to the Labour Party before deciding to run for the job herself.

In a bizarre twist it is thought likely that she will call on London voters to use their second vote for Livingstone - a ploy which had angered some in the Banks camp.