A report by the Australia Institute revealed of the $3.9 billion spent by the government on seven grant programs, $2.8 billion of that went to marginal coalition electorates.

The analysis also found the grants skewed towards the marginal seats at the expense of Labor seats and even safe coalition seats.

The report examined seven grant programs with ministerial discretion.

Three of them focused on regional areas while the remaining four were national programs.

Marginal coalition seats received $184 per person in national grant funding and $194 per person for regional programs.

That's compared with $39 and $51 per person in Labor-held seats for national and regional programs respectively.

Of the total grant funding analysed, 71 per cent was funnelled into government-held seats, 23 per cent to Labor and six per cent to electorates held by independents or minor parties.

The government has come under fire for several of its schemes, where grants were approved for marginal seats, sometimes against the advice of the department overseeing the program.

Labor has accused the government of engaging in a pattern of multi-million-dollar rorts.

The Australia Institute's senior researcher Bill Browne said the grants were skewed towards seats the government aimed to win at the next election, rather than being based on need.

"It is worrying to see grants programs awarded via ministerial discretion favour marginal and target seats so heavily at the expense of other Australians," Mr Browne said.

"Any electorate could benefit from these projects, which calls into question what criteria is being used."

The report said if every safe Labor seat was funded at the same level as marginal coalition ones, an extra $928 million in funding would have been received.

Safe seats held by the government also missed out on $626 million, according to the analysis.

"It seems a spectacular coincidence that 17 of the top 20 most-funded electorates under the regional grant program are current coalition electorates," Mr Browne said.

"Even more so that all safe coalition seats that received $25 million or more in community development grants are held by National Party members."

Australian Associated Press