The union says 180 workers at specific offices in Surrey, Kelowna, Campbell River and 100 Mile House will walk off the job during operating hours on August 7.
Affected offices including the Ministry of Forests, Lands and Natural Resource Operations in Surrey, Campbell River and 100 Mile House, as well as the Ministry of Labour, Agriculture, Health and Environment in Kelowna, and the Ministry of Transportation and Infrastructure in 100 Mile House.
Although several forests ministry offices will be hit, the BCGEU says any forest firefighting operations around B.C will not be affected.
On July 3, workers at three liquor distribution centres staged a 24-hour strike to protest the slow pace of contract talks.
The union says negotiations have stalled and wages remain the main issue for its 25,000 members who have been without a contract since the end of March.