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.