Industrial action by staff will not compromise safety at Parliament, says the service which employs them.
The pay dispute involves more than 120 parliamentary staff and includes security officers, parliamentary library staff, reception workers and messengers.
Industrial action is due to begin on Thursday, with Parliament security officers who work the night shift attending a one-hour stopwork meeting.
Parliamentary Service general manager Geoff Thorn says security managers will cover the night shift.
He says the service has indicated to the union that it is willing to sit down and talk at any point.
Public Service Association national secretary Richard Wagstaff says the union wants an expression of willingness by the employer to make an improved offer before going back to negotiations.
Mr Wagstaff says Parliamentary Service has frozen workers pay and denying their right to collectively negotiate.