The $1.6 billion Perth Freight Link announced by the Abbott Government will likely fail a mandated cost-benefit analysis, the Federal Opposition claims.
The project, which would be a traffic lights-free link between Perth Airport and Fremantle port, was one of the centre-piece infrastructure announcements in the Government's first Budget.
Shadow infrastructure minister Anthony Albanese told The West Australian that the Government's acceptance of Labor amendments to laws governing Infrastructure Australia meant that the project would now have to satisfy economic and environmental scrutiny before proceeding.
The Federal Government claimed a cost-benefit analysis by Ernst & Young on the extension of the Roe Highway - a key part of the Perth Freight Link - would have a $5.20 economic benefit for every dollar invested.
But Mr Albanese said the Ernst & Young analysis, which the Government has refused to release in full, was far from satisfactory.
"This project has not had anything like a full cost-benefit analysis," he said.
"Taxpayers' money must be spent wisely, not on the back of an envelope. This project has failed environmental tests when it has been scrutinised before and I suspect it would fail again.
"The Government's desperation to announce something for WA in the Budget led it to cut corners and when you cut corners, projects like this one start sliding."
Assistant Infrastructure Minister Jamie Briggs said Mr Albanese was making things up. "The Labor Party should stop telling fibs about our record infrastructure investment," he said.
"The Perth Freight Link is an outstanding project and it will proceed."
Finance Minister Mathias Cormann said Labor had a history of arguing against investment in genuine productivity-enhancing infrastructure in WA.
"In government Labor was the most Eastern States- centric Federal government in the history of Australia and with people like Bill Shorten and Anthony Albanese, Labor continues to be anti-WA in Opposition," Senator Cormann said.
The Government has pledged $925 million to the project, with $230 million to come from the State Government under an 80-20 funding split and another $445 million from the private sector.