Western Australia's Liberal opposition has failed to provide key details on its policy costings in a shambolic presentation two days before the state election.
Opposition Leader Zak Kirkup claims the Liberals' promises will have a net cost of just $1.4 billion over the next four years.
Just $260 million has been attached to Mr Kirkup's centrepiece policy promise - an ambitious clean energy plan which includes a target of reaching net zero emissions by 2030 and shutting down coal-fired power stations by 2025.
Labor estimates that plan alone will cost almost $16 billion and that the rest of the Liberals' promises will total about $9 billion.
At a media briefing on Thursday, the Liberals treasury spokesman Sean L'Estrange was unable when asked to provide the cost of key promises.
"My role as the shadow treasurer is to make sure that we've got the funds to be able to pay for the costings that we have committed to," he told reporters.
"If you want me to roll out the spreadsheet with every individual costing right here and now ... that was not the purpose of this presentation."
Mr L'Estrange, who has been rarely sighted during the campaign, insisted he had not been sidelined.
Treasury has costed Labor's full suite of promises at $2.4 billion over four years, a figure that will lift the state's net debt to a peak of $42 billion.
The Liberals refused to submit their policies to Treasury, instead having them costed by national accounting firm Hall Chadwick.
Liberal energy policy spokesman David Honey said much of the investment required for the party's clean energy plan would come from the private sector.
He claimed that writing off coal-fired power plants in Collie would not have a major budget impact because they were worth "virtually nothing".
"They're sunk costs. They're already in the budget, they're already in the bottom line," he said.
Other major promises to face scrutiny include an investment in public housing.
Mr Kirkup said $248 million had been allocated to build 2600 new homes - a figure that would equate to about $95,000 each.
Treasurer Ben Wyatt said such a cost was not plausible.
"I am not sure how much they think it costs to build a home in Western Australia, but the sort of money they are talking about isn't going to go anywhere near delivering on that," he told reporters.
"This is the party that is saying to West Australians, 'give us the power of veto over any future government'.
"I think anyone watching that would be very unlikely to want these guys in charge of any part of the parliament."
Mr Kirkup has conceded the Liberals won't win Saturday's election and declared he will retire from politics if he loses his ultra-marginal seat of Dawesville.
The first-term MP admitted the campaign had taken a toll on him but insisted he would continue to fight to save Liberal seats.
