"Say no to Roe!", chanted more than 100 people at a rally outside state parliament on April 22.
The rally was organised to oppose a five-kilometre freeway extension (Roe stage 8) between the Kwinana Freeway and Stock Road in Melville, south of Perth.
Speakers said the proposed extension was expensive, unnecessary and environmentally destructive. It would desecrate Noongar sacred sites and threaten the endangered species.
Corina Abraham from the Coburn Aboriginal Reference Group said: "We will not compromise on the desecration of our sacred sites." She called for Premier Colin Barnett to stop the project.
Other speakers included: Labor opposition leader Eric Ripper; Greens MLC Lynn McLaren; Nicole Hodgson from the Conservation Council of WA, and Glenn Albrecht, professor of sustainability at Murdoch University.
When transport minister Simon O'Brien appeared to receive hundreds of protest postcards, the chants of "No Roe!" picked up, continuing as he spoke.
Save Beeliar Wetlands campaigner Kate Kelly said: "This is not going to happen. We will lie in front of any bulldozer; we will put our bodies on the line.”