WHARF workers are on strike in Western Australia and Victoria over pay and safety concerns at Patrick Stevedoring sites.
The workers are taking action after the deaths of three people on the job in the past year.
Wharfies in Fremantle have walked off the job for 72 hours and have said they will also strike in Albany, south of Perth, for 48 hours on Thursday.
Workers at Melbourne's Webb Dock and Geelong also voted to strike in protest of safety and pay conditions.
Maritime Union of Australia national secretary Paddy Crumlin said the workers wanted better pay, improved safety conditions and permanent, rather than casual, employment.
"After six months of patient, reasonable and determined negotiations on our part, Patrick has refused to meet the union even part of the way," he said in a statement.
"This is not an unreasonable wage claim. In fact, wages are quite literally the least of our priorities.
"This is about the safety and wellbeing of workers at Patrick bulk and general facilities.
"This action is also about the pride in our work and the desire of any worker to have certainty in their career and the possibility of a clear path and progression in that career."
Mr Crumlin said 60 per cent of the workforce was employed on a causal basis, with no clear pathway to either part-time or permanent positions. He said many workers had been casual for more than nine years.
The workers have also received minimal training, he said.
Fremantle Port Authority spokeswoman Ainslie De Vos said two vessels could potentially be affected by the strike.
"One of the vessels in the inner harbour in Fremantle will be affected by the strike and possibly a bulk ship in Kwinana will be affected," she said.