However, it was not immediately clear if the new leader, Gordon Brown, would make her deputy prime minister when he moves into Downing Street on Wednesday - instead in his speech he pledged to make her Labour party chair in addition to deputy leader.

Accepting her new role at the special conference in Manchester, Ms Harman said she would be a "champion" for women.

Ms Harman, the justice minister, told an audience of Labour delegates: "During the campaign I heard what you said - and you want action to tackle the shortage of affordable housing, to do as much for youth services as we've done for children under five, to ensure better support for families with older relatives, to guarantee equal treatment in the workplace and action to improve our environment."

Ms Harman said it was clear that people joined Labour to have a say in politics and, in a swipe at Tony Blair's style of government, she said: "You want our plans to be debated and presented to parliament, not briefed and spun to the media.

"You want us to acknowledge the anger and division caused by Iraq, and we do."

Ms Harman said Labour members also wanted a party that will stand up for every family and one which will build consensuses in every corner of Britain.

The backbench candidate, Jon Cruddas, did suprisingly well, winning the first round and coming third overall.

Current party chair Hazel Blears was eliminated first in a complicated ballot in which second and third preferences were reallocated as candidates were eliminated. The electorate comprised three elements - the MPs and MEPs, party members, and affililated union members.

Peter Hain went out in the second round, followed by Hilary Benn.

Ms Harman promised to campaign in crucial marginal seats in the south, such as Crawley, Enfield, Basildon and Dorset.

She added: "I have always tried to be a champion for women and, as deputy leader, that's what I will do. It feels like politics has come a long way since I first entered parliament in 1982.

"Today we have 97 strong Labour women MPs but back then I was one of only 10 Labour women in a parliament of 97% men. With a top leadership team of a man and a woman, Labour once again leads the way."

Hazel Blears said she was "disappointed" about being the first candidate eliminated, but "pleased" there was a man and a woman at the top of the party.

She said: "We have picked a strong team ready to take on Cameron at the next election. I'm pleased that there is a man and woman at the top of our party.

Mr Johnson said Ms Harman and Mr Brown would make an "excellent team."

And he joked: "I said I was the best man for the job but, as in many spheres in life, there was a better woman."