Commercial fishermen are hesitant to tender for work on Western Australia's controversial shark cull because of concerns for their safety, Premier Colin Barnett says.

The State Government has issued a tender for professional fishers to catch and kill all white, bull and tiger sharks more than three metres long in certain areas along the WA coast.

There has been strong opposition to the policy, including from one man who vandalised Mr Barnett's office.

And Mr Barnett says commercial fishermen are understandably wary.

"There has been some hesitancy by people who were keen to put in tenders and some of them have pulled back," he said.

"I can understand that because there has been a lot of aggression and threatening behaviour in the community."

The Premier says such behaviour has damaged the standing of the environmental movement.

His comments come as WA activists band together to form a special unit in a bid to sabotage the catch-and-kill shark policy.

Activists plan non-violent action

The Marine Response Group will attempt to monitor and disrupt the setting of baited hooks, designed to catch sharks more than three metres long in designated areas.

Forest Rescue, Animal Amnesty and West Australians For Shark Conservation are all involved in the action.

A spokesman for the group, Ross Weir, says it is not their intention to harm commercial fishers or take violent action.

"We utilise non-violent direct action," he said.

"Having said that, this will be a risky and dangerous campaign, there will be a lot of vessels on the water.

"There will be a lot of people looking to disrupt, intervene and photograph this operation and expose it to the rest of the world."

Mr Weir says the team is determined to make its point.

"We are looking to do whatever is required to put an end to this hunt," he said.

"Any applicants that will be applying for this tender and this contract need to take very careful consideration into account as to the potential backlash and direct action tactics they will face out there on the water."

The ABC understands some commercial fishermen planning to tender for the work asked the Government whether they would be provided with security, but they were told it would make the operation too expensive.

The Government announced the new policy late last year and had hoped to have the baited hooks in place by January 10.

It now hopes to award the tenders to commercial fishermen this week.

Opposition spokesman Dave Kelly says it is a classic case of policy on the run.

"It's clear when the Government made the announcement they hadn't done the basics, they hadn't worked out the logistics and they hadn't done the finances," he said.

The Premier concedes the policy is proving "complex" but is still hopeful it will be in place by the end of summer.