Activist fights legality of cops' weapons expo powers

"Police are wielding these extraordinary powers that have just been granted to them to limit the freedoms of people like me," the WA Greens staffer told reporters on Monday.

"All I want is to be able to move through the city where I live and where I work freely."

Ms Lane-Rose has launched a Supreme Court legal challenge against extraordinary, temporary powers granted to police by the WA parliament, which also allow officers to search people's bags and vehicles in the conference area.

The case argues that WA Police did not properly apply the legal criteria when deciding to put Ms Lane-Rose on the list, and did not afford her procedural fairness before issuing her with the notice that she was on it.

"These laws were deployed in such a way that those on the excluded list were told on the day that they were excluded, with no details of the evidence or material that that exclusion was based on, and no ability to challenge that decision short of a Supreme Court action," lawyer Anna Copeland said.

The exclusion area around the weapons conference takes in the Elizabeth Quay train station and a large public bus terminal.

"We will be asking the court to consider whether this broad incursion into our clients' rights was lawful and proper in the circumstances," Ms Copeland said.

After the legal case was lodged with the court on Friday, WA police granted Ms Lane-Rose a reprieve on her ban so she could attend the weapons expo on Tuesday with her boss, WA Greens MP Sophie McNeill.

"It's important to me that I keep this case running because I think the government and the police commissioner should face scrutiny in their use of these extraordinary powers," Ms Lane-Rose said.

Ms Lane-Rose will also take part in a large anti-war protest outside the conference security zone on Tuesday, which is expected to attract thousands of people.

Organisers said there would not be a repeat of the violence outside the 2024 Land Forces expo in Melbourne, when protesters clashed with police.

WA Premier Roger Cook said people have a right to protest, but must do it safely and respect the law.

"Police are working with all groups, obviously the exhibitors, but also with groups that have got an interest in this particular area, to make sure that it can go ahead; people can protest peacefully," he said.

Under the extra powers granted for the event, police can also establish checkpoints, cordons and roadblocks, and issue lawful directions for 10 days in the security area.

Officers can also seize prohibited items deemed to be a safety risk or potentially used to disrupt the event, and homeless people will be moved on.

People who fail to comply with lawful directions could be refused entry to the event precinct or ordered to leave.

The expo, Australia's largest land defence industry exhibition, runs from Tuesday to Thursday in Perth.

Ms Lane-Rose was previously fined thousands of dollars over a foiled publicity stunt protest at the home of then Woodside Energy chief executive Meg O'Neill in August 2023.

In the days after the incident, Mr Cook said the action was carried out by "extremists seeking to terrorise".