Former WA premier Colin Barnett is likely to be asked to give evidence at an inquiry into spending blowouts on major projects and record debt and deficit under his Liberal National government.
Labor Premier Mark McGowan said further action could be taken if anyone, whether public servants or contractors, had behaved improperly and contributed to what he said was gross financial mismanagement and a dire financial position.
WA's net debt increased nearly 10-fold during the eight-and-a-half years of the Barnett government to more than $30 billion and is projected to peak at $41 billion-plus, which take many years to pay, and the record deficit is more than $3 billion.
The government's "commission of inquiry" will probe contracts, decisions and spending around 26 projects, including cost blowouts at the Fiona Stanley hospital, new children's hospital, and refurbishment of the Muja coal-fired power station that is going to be shut.
Labor said when in opposition it would order such an inquiry and is now doing so after a landslide election win in March.
"WA taxpayers have a right to know where all the money went ... how WA has gone from having the best set of finances in the nation, to the worst," Mr McGowan said.
"A whole range of projects have had enormous blowouts. I want to get to the bottom of it, of why and what decision-making was behind it and if there are further consequences and opportunities for inquiry then let the chips fall where they may.
"If there's any examples of people behaving improperly or incompetently of course they should lose their jobs."
The inquiry is being run by former WA under-treasurer and prominent business identity John Langoulant, who said the deterioration in the state's operating position and balance sheet was unprecedented and the reasons why needed to be identified.
He would invite Mr Barnett and former treasurer and now opposition leader Mike Nahan to contribute but could not force them, he said.
He denied the inquiry was a political witch-hunt, involving Labor trying to damage the Liberals, saying if the premier wanted that "they had the wrong man".
However, Mr Langoulant was appointed by Labor, who instructed him on the 26 projects to probe and terms of reference.
Mr Nahan, who was treasurer at the time of the election, said he had nothing to hide and Mr McGowan was diverting attention away from himself by demonising the former government.
"We invested in a lot of infrastructure, the new stadium, Perth children's hospital and Elizabeth Quay ... it was fully itemised in the budget and examined by the auditor general," he told reporters.
The inquiry will take six months and will likely include recommendations to prevent future debt increases.