Scott Morrison has dodged a barrage of questions about a controversial $660 million pre-election car park cash splash in marginal and coalition seats.
A scathing auditor-general's report found the scheme was not effective or merit-based.
None of the 47 commuter car park sites selected by the government before the 2019 election were picked by the infrastructure department.
The prime minister repeatedly said "ministers make decisions" when grilled on what his or his office's involvement was in the scheme.
"The auditor-general has already made his ruling on this report. Ministers were authorised to make the decisions," Mr Morrison told reporters in Canberra on Thursday.
He refused to say whether he saw a hit list of 20 marginal seats the auditor-general found was compiled in then-urban infrastructure minister Alan Tudge's office.
"These are real issues. These are things that people want us to address. And my government is addressing them," he said.
Just two of the promised 47 car parks have been completed while some of the projects have been dumped.
Twenty-seven were approved the day before Mr Morrison called the election.
Mr Tudge on Wednesday denied he knew about the marginal seat list.
The prime minister said the government was addressing one of the biggest challenges people living in cities faced.
"I'm telling you, ministers make the decisions as they should," he said.
"That's the proper authorisation of the process. What Australians are getting are more car parks. Australians are the winners."
Labor's finance spokeswoman Katy Gallagher said there was a culture of coalition ministers using slush funds in the budget for political advantage.
"People are sick of politicians buying seats. We know this is what this government's been doing with sports rorts and car park rorts," she told Sky News.
Senator Gallagher has introduced a bill to parliament which would force ministers who approve grants rejected by their departments to make decisions public.
The government has argued Labor also promised $300 million for commuter car parks before the last election.
The opposition's fund had an application process for local or state governments to prove projects were the most cost-effective use of the land.
Australian Associated Press