The Barnett Government will not extend the Joondalup rail line north of Butler before it completes the airport-Forrestfield link and the MAX light rail projects, Transport Minister Dean Nalder says.
It means that a mooted extension of the northern line to Yanchep will not happen before the middle of the next decade.
The Yanchep extension - with stations at Alkimos, Eglinton and Yanchep - was recommended as one of two "transformational projects" in the Government's draft public transport master plan, released in 2011. The other was a light rail system linking Mirrabooka to the Perth central business district and the University of WA to Curtin.
The master plan recommended that each project be completed before 2020 and said an airport rail link would not be needed before 2031. The Government has committed only to a $2.2 billion tunnelled airport rail line, which is due to open in 2020.
A decision on whether to proceed with the MAX light rail project has been deferred until after the 2017 election and it will not be completed until late 2022.
Mr Nalder said yesterday that extending the northern line would not be considered until MAX was completed.
"It's something we would like to do, but it's dependent on budgets and prioritisation," he said.
"We've announced the Forrestfield airport link.
"We must deliver on that now. Beyond that, our next most important piece of public transport infrastructure I want to deliver on is the MAX light rail."
Shadow transport minister Ken Travers said the Government's own modelling showed failing to build another northern extension would lead to thousands of extra cars on the road.
Mr Nalder made the comments while announcing the 7.5km extension from Clarkson to Butler would open for operations on September 21.
At $221 million, the project has been completed $20 million under budget.