Prison guards in Alice Springs will walk off the job over the Northern Territory government's four-year public sector pay freeze.
The strike on Saturday follows similar industrial action in Darwin earlier this week.
United Workers Union NT Secretary Erina Early says corrections officers, like many other public sector workers, have had enough.
"The levels of overcrowding and short-staffing are at a crisis point, and it's a disaster waiting to happen" Ms Early said.
"Correctional officers have a dangerous job even under ideal circumstances but at the moment the extra pressures are forcing skilled and dedicated workers to leave the industry.
"The four-year wage freeze has to go. It is completely unreasonable to expect the workers who have showed up and continue to show up to accept a pay cut for the work they do."
In strike action earlier this week, about 60 prison officers walked off the job in Darwin for 24 hours.
In response, inmates were confined to their cells and youth justice officers helped staff the facility to ensure core functions were maintained, including the delivery of meals and medications.
There was also industrial action in both Darwin and Alice Springs in May.
The NT pay freeze, for more than 20,000 public servants, was introduced in November 2020 in a bid to save more than $400 million amid ongoing territory government deficits and climbing debt levels.
It was accepted by 57 per cent of employees.