Activists and a Greens MP have threatened legal action after the Western Australia police banned at least 12 people entering a designated security area where the Land Forces weapons expo will be held in Perth from 6 October.

The police used special powers given to them by the WA government last month to ban the activists from entering the area surrounding the Perth Convention and Exhibition Centre.

Two of the activists, 18-year-old Will Shanahan and 22-year-old Matilda Lane-Rose said in a media conference held with the Greens MP Sophie McNeill on Friday they would take legal action if police and the police minister, Reece Whitby, did not revise the ban.

“We’ve sought legal advice, and we think that we have standing to pursue a judicial review into this decision,” said Lane-Rose, who works as a staffer for McNeill.

Rose told reporters the police called her on Thursday saying she had been placed on the exclusion list, despite having no plans to attend the protest against the expo, which is being organised by the WA Anti-War Collective.

The legislation used to ban her and 11 others, called the Land Forces (Special Powers) Bill 2026 was passed last month. It gives police expanded stop-and-search powers and the ability to ban people from entering a security zone that extends from the Elizabeth Quay bus port to the convention centre for 10 days.

Anyone who defies an exclusion order could face a maximum $36,000 fine and three years in prison.

Whitby said at the time the legislation was “about making sure WA Police have the powers they need to keep people safe and effectively manage Land Forces, while respecting the right to peacefully protest”.

The Land Forces International Land Defence Exposition event is held every two years and is Australia’s biggest weapons expo. The last event was held in 2024 in Melbourne, and attracted a large protest where police were accused of using excessive force.

Melbourne activists Violet Coco and Brad Homewood are among the 12 people issued an exclusion order by WA police.

The companies expected to exhibit at the expo are not listed on the Landforces website. Last month McNeill made public the list, which included an Australian subsidiary of Israel’s largest weapons company, Elbit Systems, and the state-owned company Rafael Advanced Defense Systems.

The two companies have been criticised by a former member of the UN commission of inquiry, Chris Sidoti, for being “key enablers of the Israel Defense Forces in its commission of war crimes, crimes against humanity and genocide against the Palestinian people in Gaza over the last two years”.

Shanahan, who recently moved to Newcastle from Perth, said he had not intended to attend the protest given he no longer lived in Western Australia, but now planned to do so, to defy the ban.

“I cannot sit and watch my home state be captured by global militarisation and be turned into an all-out police state,” he said.

On Friday, McNeill accused the government of using the legislation to target peaceful climate activists.

“They said that these powers were for people who had the propensity to commit violence, people who are a threat to the community,” she said.

“Instead, what we’ve seen is peaceful activists targeted … who didn’t even have any plans to be here in Perth next week. It’s outrageous.”

Lane-Rose was fined $2,000 last year after pleading guilty with other Disrupt Burrup Hub activists to attempted trespass and criminal damage at the home of the then Woodside boss, Meg O’Neill, in 2023.

Whitby and the WA police were approached for comment.