Union members at Parliament will walk off the job at 3pm on Monday in protest at a pay freeze by their employer, the Parliamentary Service.
The dispute involves more than 120 members of the PSA and includes security officers, Parliamentary library staff, reception staff and messengers.
Security officers working the night shift walked off the job for an hour last week, requiring their managers to step in.
The Parliamentary Service says it's confident that it can ensure the Parliamentary precincts remain safe during the industrial action.
