About 4000 staff of Inland Revenue and the Ministry of Business, Innovation and Employment around the country will walk off the job for two hours on Monday in a bid for better pay.
"This isn't a decision our members have taken lightly but they feel they have no choice but to take industrial action," PSA national secretary Glenn Barclay said.
"We're asking for fair pay systems and a modest across-the-board pay increase but both employers have refused, and [Ministry of Business, Innovation sand Employment] even suggested staff work longer hours for the same pay.
"Public servants deserve better than this, and on Monday they will tell their employers that," Barclay said in a statement.
Comment was being sought from Inland Revenue and MBIE.