LOUISVILLE, Ky. (WDRB) -- UPS pilots voted overwhelmingly to authorize a strike against the air carrier over the lack of a new labor contract, the Independent Pilots Association announced Friday.

But UPS says the pilots' vote is merely a "symbolic gesture" because, under federal law, the pilots have to be allowed to strike by the National Mediation Board, which is overseeing the negotiations.

"A strike is not possible without the NMB’s permission, and then only after exhausting a lengthy series of safeguards," UPS spokesman Mike Mangeot said.

The pilots' vote authorizes the union's executive board to formally request a release from federally mediated negotiations with UPS, and the discretion to conduct a strike once mediation is concluded, according to the union.

“UPS promises its customers on-time delivery, but after four years of labor negotiations, the Company has failed to deliver a contract for its own pilots,” Capt. Robert Travis, the pilots union president, said in a news release. “In a clear voice, UPS pilots have said they are willing to strike if necessary to finish the job."

The pilots voted 2,252 to 8 to authorize the strike, with just under 97 percent member participation, according to the IPA.

UPS and the IPA are scheduled to return to the bargaining table in early November with the federal mediator, according to the union.

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