WA minister MacTiernan to quit politics

Long-serving minister Alannah MacTiernan is to quit the West Australian parliament at the end of the year, closing a career that has spanned local, state and federal politics.

Ms MacTiernan says the time is right to step down though she has no plans to relax and just "make crusty loaves and bake cakes".

"I have said that in the past and it never happened," she told reporters on Monday.

"I'm probably not someone that's cut out for retirement so I'm going to take a bit of a break and I have no doubt I will find something meaningful to do.

"There's no shortage of things that I'm interested in."

Ms MacTiernan has served most recently as minister for regional development, agriculture and food and for the hydrogen industry in Premier Mark McGowan's Labor government.

She first entered state parliament in 1993 and became minister for planning and infrastructure in 2001.

In 2010 she resigned to contest the seat of Canning in that year's federal election.

After losing she was elected the mayor of the City of Vincent where she served for two years before winning the federal seat of Perth in 2013.

She decided not to re-contest Perth in 2016 but was invited to return to the state parliament in the upper house at the 2017 poll.

In 2019 Ms MacTiernan was diagnosed with breast cancer and underwent surgery and chemotherapy but said on Monday she was fully recovered and the illness had played no part in her decision.

Mr McGowan said his outgoing minister was a "terrific human being".

"She's unique, hardworking, active, passionate, engaged, friendly, unstoppable and indefatigable," the premier said.

"Alannah has left an indelible mark on Western Australia over more than 30 years of serving our state.

"Her passion and work ethic are legendary. She has never met an issue too big or too small to tackle head-on."

Mr McGowan said Ms MacTiernan had played a key role in delivering the government's agenda in the regions, refocusing regional investment towards diversification and job creation.

He said her efforts in renewable hydrogen had also been instrumental in positioning WA at the head of the pack in the global hydrogen race.

"There will never be another Alannah," the premier said.

Ms MacTiernan said in the last few weeks of her parliamentary life she would be "sprinting to the finish line".

"We have got many projects that we have on the boil and we want to get those delivered and make sure that the portfolios are in great shape to hand over to the next generation," she said.

Mr McGowan refused to speculate on who might replace her in the cabinet.