WA Liberals launch campaign with fight vow

Zak Kirkup has launched the West Australian Liberals' state election campaign with no new policies but a promise to keep fighting, days after conceding the party won't win office.

The party faithful put on a collective brave face as they gathered at the riverside Burswood on Swan on a gloomy Monday morning.

With Prime Minister Scott Morrison continuing his absence from the campaign, federal cabinet minister Michaelia Cash provided a rev-up.

"Ladies and gentleman, how good are the WA Liberals," she declared before calling for the party's candidates to join her on stage.

Ms Cash said the party's mission was ensuring WA had an "effective parliament" after the March 13 poll that would hold Premier Mark McGowan to account, mirroring the shift in rhetoric deployed by the campaign in recent days.

With polls predicting a crushing Labor victory, Mr Kirkup has accepted the likely outcome and urged voters to back local Liberal candidates to provide checks and balances on the McGowan government.

The extraordinary tactic has prompted the premier to accuse his rival of throwing in the towel.

Addressing his colleagues, Mr Kirkup acknowledged the message had been a difficult pill to swallow for some party members.

"But I tell you this as the leader of the Liberal party: I believe our foremost duty to the people of Western Australia is to tell the truth," he said.

"At no point in time do we stop fighting. At no point in time do we give up.

"If this is the sacrifice I need to make then it is worth it, because the people of WA deserve a strong Liberal Party in WA parliament."

Mr Kirkup highlighted a raft of policy promises including plans to diversify the economy, recruit 1200 police officers and build the Roe 8 and 9 highway extension.

He gave only a fleeting mention of his ambitious clean energy policy which has been publicly criticised by state and federal colleagues.

The plan includes a target of reaching net zero emissions by 2030 and shutting down coal-fired power stations by 2025.

Mr Kirkup did not announce any new policies at the launch, a fact seized upon by the premier as he revealed plans for a re-elected Labor government to establish a $100 million investment attraction and new industries fund.

"All the Liberal Party is doing is engaging in a monstrous scare campaign," Mr McGowan told reporters.

"We have been a stable, responsible, competent, sensible government over the course of the last four years and if we're re-elected, we'll do that again. They are the risk here."

A recent Newspoll published by The Weekend Australian showed Labor leading 68 to 32 per cent on a two-party preferred basis.

Such a result on March 13 would wipe out a swathe of Liberal MPs and likely result in Mr Kirkup becoming the first major WA party leader in almost 90 years to lose their seat.

He holds the seat of Dawesville, an hour south of Perth, by just 0.8 per cent, making it the second-most marginal Liberal electorate.

"If there is a Labor party returned with a super-majority, with total domination, without checks and balances, then what is at risk is the very future of our state," Mr Kirkup said.

"And the only thing that stops them will be the Liberal Party."

Deputy leader Libby Mettam comfortably holds her southwest seat of Vasse and shapes as Mr Kirkup's likely replacement to lead the party should he lose his seat.