Harriet Harman, the former social security minister, will launch a campaign in the new year to ensure that the Prime Minister addresses the issue. She will also call for Labour to come up with an alternative to all-women shortlists which were ruled to be illegal.
The campaign comes as internal Labour Party polling has begun to detect a falling away of "women's sympathy and support" for the party.
A party source said: "These women tell us they are still going to vote in the next election but their loyalty will only be secured if we move away from a male-dominated leadership."
He added: "Women supporters have picked up on the fact that Blair hasn't promoted women into any of the big spending ministries."
The Fawcett Society, which campaigns for equal female representation in politics, has published a report warning that the number of women MPs is unlikely to increase without positive action.
The report, Winning Women: Lessons from Scotland and Wales, argues that the high numbers of women in the Scottish Parliament (37 per cent) and Welsh Assembly (40 per cent) was a result of twinning constituencies. Twinning forced Labour constituencies to pick a male and a female candidate.
But the report also highlights the internal opposition that women candidates received from their own parties in Scotland and Wales. Some women even reported receiving poison-pen letters from party activists.
Mary-Ann Stephenson, director of the Fawcett, said: "The Scottish Parliament and Welsh Assembly have shown that it is possible to do politics differently. But without positive action most of those women would not be there. No party has managed to increase the numbers of women elected without some form of positive action."
Mrs Harman, who has written an article for the Labour modernisers' magazine Renewal to be published in January, said: "We still need more women candidates for parliament. Our goal must be equal numbers of men and women in the PLP.
"We have no positive action mechanism for the upcoming round of selections."
Harman is worried that many of the parliamentary vacancies coming up because of retirement or MPs moving to the Welsh Assembly and Scottish Parliament will not be capitalised on if Labour does not introduce a similar system to twinning for UK elections.
TONY'S IDEAL WOMAN, PAGE 17