Safeway and Albertsons workers in several cities in Colorado went on strike after nine months of negotiations. 

In the last week of May and the first week of June, Safeway and Albertsons workers in Metro Denver, Boulder, Broomfield, Castle Rock, Conifer, Evergreen, Fountain, Grand Junction, Idaho Springs, Parker, Pueblo, Salida, Steamboat Springs, and Vail all voted to authorize an unfair labor practice strike, the UFCW Local 7 Union representing the workers said in a letter.

President of the Union, Kim Cordova, said in a letter that Local 7 negotiators offered the company the chance to avoid a strike by offering retroactive pay and benefit increases for workers, but that offer was rejected.

The letter also said that chronic understaffing had an impact on workers and buyers across stores and that 99% of Metro Denver workers voted to strike.

The letter added that the strike could spread to stores throughout the state. Workers in Estes Park, Fountain, two in Pueblo, and a Safeway distribution center in Denver, walked out on Sunday and, according to the Colorado Sun, were joined by employees from Castle Rock and the Littleton location on Mineral Ave on Monday. 

In a statement sent to Denver7, a spokesperson for the company said they remain "committed to productive discussions" with the union, and are "disappointed" that the union has chosen to strike some stores, and "allegations of unfair labor practices are without merit."

Cordova said the two parties may soon return to the bargaining table. Both supermarket chains are owned by Albertsons Companies.