Flight dispatchers at UPS are ramping up pressure in contract talks by taking a vote saying they would be willing to strike.

However, the flight dispatchers don't yet have the legal authority to strike under the Railway Labor Act that governs their negotiations.

Instead, a strike vote is intended to turn up the heat in labor talks.

UPS management said the vote is “simply a show of solidarity common in airline negotiations; there is no threat of a strike.”

Dispatchers prepare pre-flight plans for aircraft, plotting the plane’s course, calculating the fuel needs, coordinating with maintenance and tracking each flight, according to the Transport Workers Union, which represents dispatchers at UPS. A flight can’t depart until it has the approval of the dispatcher and the pilot in command.

Dispatchers at UPS want “pay parity” with dispatchers at major carriers including Delta and American, according to the union. UPS dispatchers at top scale make about 26 percent less than their counterparts at major carriers, the union said. The union also wants the workers’ pension plan to be fully funded.

UPS management said it “continues to negotiate in good faith for a contract that is good for our flight dispatchers, our customers and our company. We are confident talks will be completed without disruption to our customers.”

UPS has its headquarters in Sandy Springs but its flight dispatchers are based at its air hub in Louisville, Ky.

The flight dispatchers voted 81-to-0 last month in favor of authorizing their union leaders to call a strike if necessary, TWU announced Monday.

Transport Workers Union Local 549 has been negotiating with UPS for more than three years.

In order to gain the right to strike, the union would need to ask to be released from federal mediation and if approved, wait through a cooling-off period.

UPS pilots took a strike authorization vote in 2015 before reaching a contract deal. In 2016, aircraft mechanics at UPS took a strike authorization vote. Federal mediation on the mechanics' contract continues, after the mediator declined two requests by the union to be released from mediation.

Negotiations began last year on a much bigger UPS Teamsters contract, which expires Aug. 1, 2018. Teamsters contracts cover a total of about 260,000 UPS employees.