Stores in Colorado Springs, Fort Collins, Greeley and Longmont will hold strike-authorization votes tonight and tomorrow morning.

On Monday, new Safeway locations joined UFCW Local 7's strike efforts, bringing the total to six locations across the state with more expected in the coming days. It's the first Safeway strike in almost 30 years.

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.