The Waikato and Bay of Plenty will likely get more representation from the Labour party in Parliament following the next election.

At its annual conference in Christchurch at the weekend, the party passed a remit that will ensure its MPs list reflects the geographic location of the country's population.

There are about 650,000 people in the Waikato-Bay of Plenty region, and there are only two Labour list MPs - Sue Moroney and Nanaia Mahuta - representing them.

By contrast, National has nine MPs covering the region, each incumbent in the Waikato, Taranaki-King Country, Taupo, Rotorua, Bay of Plenty, Tauranga, Coromandel and both Hamilton electorates.

Barring a rout at next year's election, Labour will have at least a couple more local MPs to reflect the region's growing population.

"It guarantees that there will be more Labour MPs from this area on the party list," Ms Moroney told the Times.

"For whatever reason there are a lot of people wanting help from an MP who for whatever reason don't want to deal with a National MP, and there are only myself and Nanaia there for them, which has not been good enough. They are going to get a much better deal out of us."

At the conference Labour also approved a gender quota, which will ensure 45 per cent of its MPs are women after the next election and at least 50 per cent are women in 2017.

A late amendment to bring the 50 per cent level forward to 2014 was defeated.

Labour leader David Cunliffe said in the current Labour caucus 41 per cent of the MPs were women, so 45 per cent would not be a hard target to meet, especially with a lift in Labour's share of the vote from 27.48 per cent in 2011, and to 50 per cent in 2017.

"I will personally be backing that."

Ms Moroney said following a leap in numbers following the introduction of MMP in 1994, the number of women in Parliament had since plateaued.

"We know we can do better. The female population in New Zealand is 51 per cent, and we can't pretend to be representative if we can only get 41 per cent."

Party president Moira Coatsworth said the target would be achieved by calculating the gender mix at various levels of support and taking into account the likely electorates Labour would win.

The list would be selected in "bands" of five, with an equity check after each band.

Mr Cunliffe said it was possible the party could fall outside its target by a small amount because of that process, but if so, male candidates who were elected would not be pressured to stand aside.

Ms Coatsworth said skills were the first thing to take into account in selecting candidates.

"It's 120 years this month since women got the vote but we still have less than a third of women in the New Zealand Parliament. For the last 120 years women have missed out. This is about getting women equity.

"It's not about merit or representation, it's about representation that includes merit."

She said Labour had a good record, but wanted to keep going with that by lifting it to 45 and then 50 per cent.

The conference also approved a trial plan for a separate list of Maori candidates, determined by Maori, that would then go as an "input" to the final list moderating committee.

Delegates are yet to vote on other constitutional remits that would require candidate selections to consider a range of factors including age, sexual orientation, ethnicity and geographical spread.