The Bob Brown Foundation is seeking legal advice after being threatened with a $50,000 fine in a letter from Mr Cocker requesting information relating to safety issues at recent protests at Que river in the Tarkine in February.

Dr Bob Brown accused Mr Cocker of "targeting" the foundation.

"He's too busy on this political mission to do his proper job which is responding to real concerns about workplace safety in construction sites," he said.

"They're trying to take out our foundation and that won't work."

In State Parliament on Wednesday, the Greens successfully tabled a complaint it made to the Integrity Commission about Mr Cocker and government ministers Elise Archer and Guy Barnett in relation to a Worksafe prohibition notice he issued banning the Bob Brown Foundation from forest protests due to safety concerns.

The seven-page letter contains eight complaints.

The prohibition notice against protesters was set aside by mutual agreement in the Hobart Magistrates Court.

Greens MHA Rosalie Woodruff asked if Ms Archer sought advice from the Solicitor-General.

"There are still serious questions hanging over this referral," she said.

"The Minister for Justice oversees the regulator.

"She must reveal whether she sought legal advice from the Solicitor General prior to WorkSafe's legal over-reach and misuse of public resources in this matter."

Ms Archer said the complaints were "highly defamatory" and referred to a letter from the Integrity Commission accusing the Greens of using the commission for "political purposes"

Ms Archer said Mr Cocker made decisions independent of the government.

"Contrary to the claims from the Greens, the government did not refer the matter to the Workplace Health and Safety regulator," she said.

"As members know, the Greens have referred this matter to the Integrity Commission in an overtly political manner, so I would ask that the Integrity Commission now be given the opportunity to undertake its work without any further politicisation."

Unions Tasmania have expressed no confidence in Mr Cocker for failing to protect Tasmanian workers.

The Construction, Forestry, Maritime, Mining and Energy Unions says safety in Tasmania's construction industry lags well behind other states.

Unions Tasmania secretary Jessica Munday said Mr Cocker's job needed to be done by a person "completely independent and focused on worker safety".

"It is unprecedented for us to express no confidence in the regulator," she said.

"Rather than taking strong action to protect workers, he has chosen to prioritise action on protest activity instead.

"The position is too important to be politicised.

"Workers, unions and the community must have confidence that the regulator will adequately respond to the myriad of safety concerns in Tasmanian workplaces as a matter of priority."

CFMMEU state organiser Richie Hassett said standards in Tasmania's construction industry were 20 years the rest of Australia in amenities scaffolding and electrical standards.

'None of them is adhered to - the inspectorate is incompetent - they don't have a background in the construction industry and lack resources," Mr Hassett said.

"We have been complaining for six or seven years and if anything we've gone backwards.

"We've asked for pins (provisional improvement notice) on building sites where laws are being breached and every time they come up with an excuse.

"It beggar's belief that after one so called breach by protesters they get a notice."

Mr Cocker has been contacted for comment.