Thousand of Costco Teamsters across the U.S. are preparing to strike by the end of the month if the company does not present a "fair contract offer," the union says.

Members of the Teamsters union have authorized a strike against Costco on Feb. 1 unless they reach a deal with the warehouse retailer before the current contract expires on Jan. 31.The union said 18,000 Costco workers are set to go on strike at 56 of the company’s warehouse stores spread across five states after 85% of members voted to authorize a strike.