Clashes between police and protesters at the site of the contentious Roe 8 road project in Perth’s south look set to escalate, despite a High Court challenge to the multibillion dollar project failing.
WA Environment Minister Albert Jacob says land clearing could be complete by the March state election as opponents vow to keep fighting.
Fences starting going up last week for Roe 8, which will be WA's first toll road despite state government indecision on the rest of the route for the $1.9 billion Perth Freight Link project connecting Roe Highway to Fremantle port.
Protest group Save Beeliar Wetlands lost its bid to challenge state environmental approval for the road in the High Court on Friday but is clinging to hope it can still stop the project.
In the last roll of the dice. The group is also pursuing a legal challenge in the Federal Court over commonwealth environmental approval.
Convenor Kate Kelly conceded it was a long shot and the High Court bid had been the best chance.
"We're not going to give up," she told reporters.
"We're not walking away from this in a legal sense and we're not walking away from this down in the wetlands."
Ms Kelly called for calm at the site.
After trucks rolled in last week, many protesters were arrested and more were issued move-on notices as they kicked down fences and obstructed work, with some locking themselves onto equipment.
Ms Kelly urged the state government not to clear land until after the March state election.
"There's a legal matter on foot so they have no mandate," she said. "We're very close to the caretaker period. If Labor get in, this project is in doubt.
"So what we really need to see here is a bit of breathing space for the police, the community, the animals and the ecological values of the wetlands."
But Mr Jacob said the Liberal government was still in power and would be getting on with the project.
Asked if the land could be cleared before the state poll in less than three months, he said: "I think that's highly likely".
"But I wouldn't be able to give you a definitive answer because that would come down to the Department of Transport and the contractors."
He told Save Beeliar Wetlands, Labor and the Greens to "accept the independent umpire's decision".
Save Beeliar Wetlands now faces a substantial legal costs bill but Mr Jacob ruled out waiving it.
"The state has had to expense significant taxpayer funds pursuing these matters through a whole range of appeals so the state will be seeking reimbursement," he said.