United Parcel Service Inc. workers voted overwhelmingly to authorize a strike, a negotiating tactic that gives the company’s 280,000 Teamsters members an option to walk out if the current contract talks fail.

“This does not mean we will strike,” Denis Taylor, director of the Teamsters package division, said on a webcast announcing the results. “It means we have a credible strike threat.”

More than 90% of votes cast authorized the strike, which grants the negotiating committee the power to call for a work stoppage after the current contract expires.

The two sides are negotiating to replace a five-year contract that expires on July 31. They have reached tentative agreements on some noneconomic issues but have only recently begun discussing topics like pay raises and health benefits.

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