Prison officers are the latest frontline workers to mount industrial action after turning down the West Australian government's pay deal.
The WA Prison Officers Union on Monday began the first stage of a campaign involving thousands of members that could escalate to "large-scale strikes".
Officers will cease the practice of arriving at work half an hour early, instead turning up at their rostered start time.
The union says this will delay shift changeovers and disrupt the daily running of prisons.
Almost 80 per cent of union members voted against the Cook government's offer of a minimum 3 per cent pay rise and one-off $3000 cash bonus.
They also want greater incentives for officers to work in the regions and are opposed to proposed restrictions on shift-swapping.
"Prison officers have had enough - they are ready to fight for what they deserve," union secretary Andy Smith said on Monday.
"This is the highest percentage we've ever seen vote in favour of industrial action.
"Our members deserve better pay and conditions to be able to serve the community, doing one of the state's most dangerous jobs."
The union is set to hold talks with the government this week and has said any further industrial action won't put officers or the community at risk.
"We've all seen and heard about the atrocious state our prison system is in and the government needs to invest in a workforce, that is already short-staffed, to ensure we can attract and retain officers," Mr Smith said.
"If the government fails to respond, we will not rule out large-scale strikes into the future."
Nurses, midwives, police officers and firefighters are still yet to accept the same pay offer.
The nurses union was last month fined $350,000 for organising a strike outside state parliament in defiance of the Industrial Relations Commission.
