A multi-billion-dollar Federal Government program to deal with traffic congestion has become the latest scheme at the centre of pork-barrelling accusations.

Key points: Analysis by Labor shows 83 per cent of the $3b program went to government and marginal Labor seats

Analysis by Labor shows 83 per cent of the $3b program went to government and marginal Labor seats The funds were not allocated through a competitive grants process

The funds were not allocated through a competitive grants process A spokesperson for the Minister said road and rail projects are decided by the government

Labor claims the Coalition's Urban Congestion Fund unfairly benefited the government ahead of last year's federal poll.

Opposition infrastructure spokeswoman Catherine King said Labor's analysis of the way the money had been spent showed 83 per cent of the funds went to Government and marginal Labor seats.

"This is rorting on a nuclear scale," Ms King said.

"This was a $3 billion funding program that has seen billions of dollars poured into Liberal Party seats and Liberal Party target seats just before the election."

Ms King said over 28 per cent of the national funding went to four marginal Liberal seats.

They were the Victorian seats of Higgins, Deakin and La Trobe and the South Australian seat of Boothby.

Labor claims the only regional Victorian seat to get funding was Corangamite, and safe opposition seats were overlooked.

Opposition infrastructure spokeswoman Catherine King described the spending as "rorting on a nuclear scale". ( ABC News: Marco Catalano )

A spokesman for Infrastructure Minister Alan Tudge accused Labor of making similar decisions targeted for political purposes.

"Federal Labor made election promises for close to 60 urban projects, all of which to our knowledge were in Labor or target seats," the spokesman said.

"Road and rail projects have been decisions of government for decades under Coalition and Labor governments."

The spokesman said the funding went to "crucial projects".

In the past, Ms King has faced questions of her own about grant allocations when she was regional services minister.

The Australian National Audit Office found she provided more than $90 million for projects that were not recommended by an independent panel, as part of the Regional Development Australia Fund.

But she has defended her management of that scheme, arguing that she had the final ministerial discretion and the funding did not favour Labor seats.

"So worried was the Abbott-Turnbull-Morrison Government about the project decisions that I made they then ratified those decisions, signed contracts with every single one of those projects, funded them and built every single one of them," Ms King said.

The Government maintains there are many Urban Congestion Fund projects that were funded in Labor seats and only one direct representation for funding came from a Labor MP.

The Urban Congestion Fund is billed as a program to reduce travel time for commuters, delivering a more reliable road network and reducing transport bottlenecks.

The money for the fund is not allocated through a competitive grants process.