Colin Barnett against quota for women

Women make up less than a third of Western Australia's parliament but Liberal Premier Colin Barnett says a quota is not needed to boost their numbers.

Labor voted during its national conference at the weekend to ensure women hold half of its positions within the next 10 years.

Western Australia has 28 women in its 95-seat parliament, making it the fifth highest state or territory in terms of proportionate female members.

Mr Barnett conceded it was often difficult for women to enter politics, particularly if they had young children, but said the gender divide in state parliament would diminish with each election.

"I think a lot of very talented, enthusiastic and hard-working young women have entered parliament over the last two elections and I think they're there to be seen," Mr Barnett said on Tuesday.

Minister Helen Morton, who sits in the upper house and holds three portfolios, is also not in favour of a quota.

She said women just needed the encouragement and support to put their hand up and be pre-selected on merit.

Making the hours more work-friendly in parliament and getting women to join political parties would also be a good first step, she said.

"Never once was there any barrier put in front of me," Ms Morton said.

"I think that some women might find the combative nature of politics difficult but it's actually not difficult if you have a good understanding of community, community needs and the issues that you want to pursue."

There are 14 Labor, 10 Liberal, three Nationals and one Greens female state MPs in WA.

The ACT has the highest proportion of women in its parliament, followed by the Northern Territory, Victoria, Tasmania, WA, Queensland, NSW and South Australia.