Mr Tudge, now the Education Minister, has on Wednesday appeared before the media for the first time since the release of the Auditor-General's report exposing serious flaws in the high-profile program.

He was in charge of the criticised car park scheme, which Labor has described as "professional rorting" or "sports rorts on an industrial scale".

In June, the Australian National Audit Office found the sites chosen in the scheme had not been selected on merit and focused on Coalition held or marginal seats. It also found Mr Tudge's office kept a "top 20 marginals" tracking sheet for awarding projects.

The minister told reporters in Parliament House on Wednesday he was "not aware" of such a list and insisted the car park sites "were chosen on need".

"The Auditor-General also said that they were all lawfully based," Mr Tudge said. "I think 33 of them were ticked off by the department before coming up for decision and we took those to the Australian people and the Australian people voted for them.

"And most of those were based in Melbourne where the need was the greatest and it was off the back, obviously, of Infrastructure Australia suggesting that commuter car parks are an important mechanism to address congestion in our cities."

Labor's spokesperson on urban infrastructure, Andrew Giles, is not accepting the explanation.

"It's just a complete joke and a farce that he can maintain this even now," he said.

"If he didn't know about this list, there is only one person who could have known, Mr Morrison, the Prime Minister."

The audit referred to a November 2018 meeting in which staff from the offices of Mr Tudge and the Prime Minister went through a spreadsheet identifying potential projects.

The spreadsheet included the department's suggestions as well as projects Mr Tudge's office had identified.

"It's time for Mr Morrison to come clean and explain exactly what he knew about this rort and explained to the Australian people his role precisely," Mr Giles said. "Australians deserve nothing less."