Labour's new rule to ensure at least half of its MPs are women by 2017 is likely to lead to increased pressure on males such as Phil Goff and Trevor Mallard to quit Parliament to make way for fresh male talent.
Under the rule, passed at the annual conference in Christchurch, Labour will seek to ensure at least 45 per cent of its caucus are females after the 2014 election, rising to 50 per cent after 2017 - meaning most of the new candidates likely to get high places on the party list or selection for safe electorate seats will be women.
That will mean the only way to get a significant intake of new male MPs is either by dumping some sitting male list MPs to unwinnable places on the list or pushing electorate MPs to retire from politics to open up more seats.
Among those likely to come under pressure to allow that to happen are Mr Mallard, the Hutt South MP, and Mr Goff, the member for Mt Roskill.
But both are digging their heels in and their local electorate committees are likely to protect them against any move from head office.
On current polling of about 34 per cent, Labour could win 41 seats in 2014 - seven more than at present. To meet the 45 per cent threshold, 19 of its MPs would have to be female - leaving only two of the new seats for males.
Labour leader David Cunliffe has said he would have discussions about retirements with MPs at a later stage, but one said the recent flurry of retirement announcements in National had prompted talk within Labour about its apparent inability to do the same to ensure renewal.
So far only Ross Robertson has announced he will leave Parliament next year. Mr Mallard has already said he will stand again. Yesterday, Mr Goff said he intended to stand again and had the full support of his electorate committee.
Labour Party president Moira Coatsworth said Labour already had 41 per cent women in caucus and it wouldn't take much to hit the target.
A proposal to hold a referendum on republicanism was not decided on at the conference and will go to Labour's policy council. The conference also backed a Law Commission review of abortion laws.