A fall in the number of fly-in, fly-out (FIFO) passengers using Perth Airport has sparked calls for the Government to rethink its $2 billion Airport Rail Link project.

The Government has promoted the project as a boon for FIFO workers but the resources downturn means fewer are using the airport, which is also being blamed for Perth Airport reporting its first fall in quarterly passenger numbers in twelve years.

Federal Greens senator Scott Ludlam supports having rail to the airport but says ploughing ahead when FIFO passengers are declining is "short-sighted".

"I think Premier Colin Barnett should use this opportunity to rethink his public transport priorities," he said.

"It's a very expensive capital works project, the patronage numbers are uncertain and a lot more Perth residents would benefit from the Perth light rail project.

"We know that the numbers for the MAX light rail project stacked up and that with private sector funding we could actually get that project back on the tracks very quickly."

Both the MAX light rail and Airport Rail Link were key Liberal Party election promises at the last state election but the Government has since shelved plans for light rail, citing worsening economic conditions.

Mr Barnett has said the Government would not make a decision on whether to build the light rail system until 2017, the year of the next state election.

The Airport Link will run as a spur off the existing Midland line near the Bayswater Station, tunnelling to the airport and then on to the marginal seats of Belmont and Forrestfield.

Last week Liberal MP Rob Johnson called on his Government to dump the Airport Rail link, saying it could not be justified in the worsening economic conditions and as state debt continues to grow.

Independent assessment needed says CCI

WA Chamber of Commerce and Industry chief executive Deidre Willmott said an independent body was needed to assess the infrastructure needs and whether the rail link should continue to be the number one priority.

"What's really important is to look at why a particular piece of infrastructure has been planned and whether timing-wise that remains the key priority," she said.

"So our concern would be that we don't really know what the drivers of that railway line were and whether those needs are as pressing as they are now or whether maybe there other infrastructure in Perth that might actually help with the growth of the city and provide a greater return on that investment in the near term."

But the Premier said there would be no rethink, arguing the Airport Link was not just about FIFO workers.

"One of the fastest growing areas of Western Australia is the eastern suburbs and that will provide a rail station around Belmont," he said.

"It will provide a station at the airport which is important for fly in, fly out and all travellers and it will have a Forrestfield station.

"So that's the project we are going to build and when we've finished that we will build the next big urban transport project and that will probably be the light rail or the dedicated bus service through the northern suburbs, whichever one we choose."

The Government says construction on its Airport Link project will start next year, with the first trains operating by 2020.

