A list of the coalition government's top 20 marginal seats guided its $660 million project to build car parks at suburban train stations.
It allocated money to electorates before projects were finalised, the Australian National Audit Office on Monday told a Senate hearing.
Treasury pushed for an open and competitive tender but the infrastructure department rejected this approach, senior ANAO official Brian Boyd said.
He also said the office of then-urban infrastructure minister Alan Tudge started with a sheet of "top 20 marginals" to be canvassed for funding.
This approach was also used for the government's broader multi-billion dollar Urban Congestion Fund.
Targeted electorates were asked to put forward projects for funding in the lead-up to the 2019 election.
The prime minister's office was also involved in canvassing marginal seats, using the same staff as those linked to the government's sports rorts saga.
"To some extent, it appeared there was almost like there was a menu," Mr Boyd said.
"In quite a number of cases they would have 'here's the electorate, here's the project, here's the dollars' but in some cases they didn't yet have the project identified."
One of the electorates canvassed for a car park didn't have a railway station in it. But all of the projects ultimately chosen had a railway station or line within their boundaries.
Treasurer Josh Frydenberg suggested four sites in his electorate, while fellow frontbencher and Hume MP Angus Taylor proposed two sites that were in neighbouring electorates.
Mr Boyd said after current Urban Infrastructure Minister Paul Fletcher took on the portfolio, he became concerned project costs were much higher compared to when they were first approved.In some cases, the cost was higher even though fewer car parks than initially announced were to be built.
Treasurer Josh Frydenberg speaks to the media during a press conference at Parliament House. Source: AAP
None of the 47 sites promised at the last election were selected by the infrastructure department, an audit previously showed.
By the end of March this year, just two out of 44 selected for funding had been built.
Nearly two-thirds of the sites selected were in Melbourne, despite Sydney being identified as having the most congested roads in the country.
Of the overall sites, 77 per cent were in coalition-held seats.
Government Services Minister Linda Reynolds said she rejected the idea the scheme only favoured the coalition.
“There were many Labor-held towns and regions that were also at the benefit of [the program],” she told reporters in Perth on Monday. “I do not think that's an adequate characterisation.”
“It was done, as I understand it, absolutely in accordance with the guidelines, and it was done transparently.”
With SBS News.