Mark McGowan has challenged the Liberals to come clean on whether their airport rail spur was contingent on Federal funding during a stoic defence of Labor's Metronet plan.
In a further escalation of the public transport election war, the Labor leader described the Liberal Party radio advertisements targeting the Metronet airport rail stations as "lies" and "beneath the Premier of this State to endorse".
The advertisements describe the airport rail station as 1.5km from the airport terminal.
"This claim is simply not true," he said.
"My Government will build a station at the new integrated Perth Airport with the domestic terminal joined to the international terminal."
Shadow transport minister Ken Travers said advice from Perth Airport was that the existing domestic terminal would close by 2020 when it would move to the international side.
Labor's plan was for the airport rail station to "come up into the new domestic terminal" with an internal people movement system, currently being development by the airport, used to transport passengers within the combined building.
"We've had numerous discussions, frank discussions with the airport," Mr McGowan said.
"We know it can be done and that is what we'll do."
Mr McGowan said he did not believe the Liberal Party would build its airport rail link after saying late last year that no rail line was needed to the airport until 2031.
He said Premier Colin Barnett and Transport Minister Troy Buswell needed to explain how the Liberal airport rail link was to be funded.
"I'm told there is a large component of their plan that requires Federal funding and they need to explain if that is or is not the case," he said.
Mr McGowan said Metronet was not contingent on Federal money, though it would apply for and welcome any Commonwealth contribution.
Mr Buswell this morning accused Labor of not submitting the full Metronet plan to Treasury for costing this morning because it had yet to release the costings for its Yanchep and Byford extensions.
Mr McGowan said the two spurs were part of the five priority projects Labor had costed at $3.8 billion.