The State Opposition has questioned why the Barnett Government has put out to tender a $90,000 economic analysis on the already-commissioned $1.9 billion Perth Freight Link project.

The Government last month called for tenders for a five-month contract to prepare an economic analysis report on the Perth Freight Link, including the proposed Fremantle Tunnel.

Perth Freight Link was conceived as a joint federal-state road project under former prime minister Tony Abbott, and remains the top priority of Infrastructure Australia, the federal agency prioritising the nation's major infrastructure projects.

But the project remains stalled despite a $1.2 billion commitment from the Federal Government after environmental approvals were declared invalid by the WA Supreme Court.

The Opposition and a range of critics have long argued the federal and state commitment to the project was done without proper economic, transport or environmental analysis.

Opposition Leader Mark McGowan said this later tender showed how flawed the project planning had been.

"It's extraordinary that they do the analysis after they announce $2 billion worth of spending," he said.

"West Australians should be very concerned that the State Government has done this."

Mr McGowan said the Government spending another $90,000 on an economic analysis on an already commissioned project "defied belief".

Freight Link affected election result: McGowan

The Perth Freight Link was supposed to provide a seamless freeway from Perth's industrial east to the Fremantle Port.

It faced a backlash from environmentalists concerned about the damaged caused by crossing part of the Beeliar Wetlands, and from householders and businesses along Leach Highway who faced having their homes resumed for road widening.

Built in three phases, it would first extend Roe Highway to Stock Road, then along Stock Road to Stirling Highway and finally across the river.

The Government committed to stage one, shelved stage two, and offered no plan or timeframe for stage three.

But in April this year, the Federal Government offered an extra $260 million to part fund a 3-kilometre tunnel under the suburbs of Beaconsfield and White Gum Valley, limiting the impact on houses and businesses.

With just eight months until the next state election, the timing and future of the project remains uncertain.

The Government has appealed against the Supreme Court's decision invalidating the environmental approvals.

If dismissed, the approvals process will have to be completed again, making it increasingly unlikely the project would commence prior to the March 2017 election.

Mr McGowan is urging Prime Minister Malcolm Turnbull to abandon the project.

He said voting results in federal seats affected by the project showed it was not wanted.

"The people of Fremantle, the people of Brand, the people of Burt, all rejected the Perth Freight Link and they were the electorates affected," he said.

Transport Minister Dean Nalder has been contacted for comment.