Parents and school community members were unhappy no Labor representative turned out to address a meeting about the future of Perth Modern School.

About 150 parents asked questions of a panel, including Treasurer Mike Nahan and Education Minister Peter Collier, Greens representative Alison Xamon and Julie Matheson from the Julie Matheson for Western Australia Party.

Alannah MacTiernan was expected to represent Labor, but did not turn up.

Parents are concerned about WA Labor's election commitment to move the school to a high-rise building.

Under the proposal, students from Perth Modern School, located in Subiaco, would be relocated to a new school — leaving the old site to become a public secondary school by 2020.

The proposed new school, Perth Academic College, would be located at the Perth City Link development.

Spokeswomen for the Perth Modern School Action Group of Concerned Parents, Emma Gregory, said the turnout demonstrated how serious this issue was.

Unhappy parents and school community members gathered in North Perth to discuss the future Perth Mod school. ( ABC News: Tom Wildie )

"Thirty per cent of the parent community turned out, which is indicative of how seriously we're taking this issue," she said.

Ms Gregory said it was disappointing Labor did not have a representative at the gathering to hear concerns from parents.

"We were really hoping to hear from the Labor Party and have them explain the policy to us," she said.

Ms Gregory criticised Labor for proposing to combine Scitech and what would be the new Perth Academic College.

Both Dr Nahan and Mr Collier reaffirmed the Liberal's commitment to keep Perth Mod, with Mr Collier telling parents: "I will be in the trenches with you on this one" if his party loses power on March 11.

"My issue with this is not political," Mr Collier told the meeting.

"Perth Mod is sacrosanct, leave it alone.

"Perth Mod, in it's current state, will cease to exist after the election if Labor win."

Dr Nahan questioned the design of the proposed building.

"You would need to have elevators like aircraft carriers," he said.