Thousands of unionized Southern California grocery workers voted to authorize a strike as contract negotiations with several chains drags on.

Renegotiation of the contracts covering roughly 47,000 employees represented by the United Food and Commercial Workers International Union began in late January. The contracts representing those workers expired in March, with the union dissatisfied with the proposals presented to it. The proposals included a less than 1% raise amounting to an additional 60 cents per hour.

"This vote prepares all of us to take action if the companies continue to commit unfair labor practices that undermine your ability to get the wages and benefits you need." UFCW Local 770 told members in a release. "We are set to meet with Ralphs and Albertsons/Vons/Pavilions again on March 30th and will keep you updated as bargaining progresses. We look forward to reaching a fair agreement within a reasonable time."

The union told members to continue to work as negotiations resumed and that the strike would serve as a "last resort" during negotiations. The union also stated that it had a support fund to aid striking workers.

Albertsons Companies (ACI  ), owner of three chains currently in negotiations with the UFCW, has called the union's proposal that included a raise of $5 per hour "unrealistic." The company has said that it has begun to prepare contingency plans, including seeking temporary workers, hoping to keep stores open during the strike.

Meanwhile, Kroger-owned (KR  ) Ralphs told the Los Angeles Times that the vote created an "unnecessary concern for our associates and communities." The chain stated that it was still focused on striking a deal with workers before the strike begins.

The strike announcement comes after the year of the "great resignation" and after a historic surge in labor organization. From Deere and Company (DE  ) to Kellogg's (K  ), companies faced increasing pressure from labor unions to negotiate higher pay increases and better benefits. The sudden surge in labor activity has contributed significantly to higher starting wages in many companies throughout the U.S.