With the clock winding down toward Saturday night's deadline for new contract negotiations, a Colorado union has announced locations where grocery employees are set to walk off the job on Sunday in protest.

Union members of the United Food and Commercial Workers (UFCW) in Southern California and the Pacific Northwest have voted this week to authorize a worker strike against Kroger and Albertsons stores, Supermarket News reported.

Safeway workers are striking at the same time as contract negotiations between workers and King Soopers are coming to a head. The union is negotiating with King Soopers and parent Kroger after a strike in February. That strike lasted almost two weeks before a deal was reached to pause the labor action for 100 days. That pause expired last month.

Workers at Albertsons, Pavilions, Ralphs and Vons grocery stores will begin preparations on Thursday for a possible strike.

Pueblo and Pueblo West Safeway workers have joined a United Food and Commercial Workers Local 7 strike seeking better pay, staffing and benefits.