Several Kootenay ferries are moving to a reduced schedule as a job action begins in the middle of an ongoing labour battle.

The ferries at Upper Arrow Lake, which run between Galena Bay and Shelter Bay, began a 50 per cent reduced service as of 3 p.m. on Friday, which means every second round-trip will be cancelled.

The Kootenay Lake ferry that runs between Balfour and Kootenay Bay will have 50 per cent reduced service beginning at 6 a.m. on Sunday.

Also on Saturday at 5 a.m., the ferries at Needles, Arrow Park and Adams Lake will begin a reduced schedule.

The job action is the latest move by the B.C. General Employees' Union, which is in negotiations for a new collective bargaining agreement with Western Pacific Marine and WaterBridge Ferries.

Western Pacific Marine employees 80 BCGEU members on the Kootenay Lake ferry as well as on cable ferries at Glade and Harrop. Those cable ferry routes are considered essential services and won't be impacted by the job action.

WaterBridge meanwhile has 90 union workers for its ferries on the Arrow Lakes as well as one northeast of Kamloops at Adams Lake.

The union has been threatening strikes since September when its Western Pacific Marine members first voted in favour of a 72-hour strike notice.