DALLAS (CBSDFW.COM) – Southwest Airlines is asking a federal judge to order the air carrier’s mechanics union to stop disrupting operations.

It’s all part of a lawsuit the airline filed Thursday, more than two weeks after it says the mechanics union, the Aircraft Mechanics Fraternal Association, AMFA, started writing up more maintenance problems on aircraft.

Rogge Dunn, a Dallas attorney specializing in labor law says, “It’s definitely upping the ante.”

Southwest says the problem is directly tied to the fact that contract negotiations with AMFA have dragged on for six and a half years.

In its lawsuit, the airline says after contract negotiations with the union didn’t go well this month, it noticed a pattern.

“The number of write ups for minor interior systems – i.e. a missing row number on an airline that does not assign seats spiked almost 400% to 500%… It quickly became clear as these unusual write ups spread across Southwest’s stations that something coordinated was beginning to occur.”

The airline says it has had to cancel and delay flights because an average of 46 aircraft were removed from service between February 11-27, which is much higher than the normal average of 14.

Southwest says anytime more than 35 of its 752 aircraft are out of service, it’s impossible to meet its customer service obligations.

In a statement, Southwest’s Vice President of Labor Relations Russell McGrady said, “We will not stray from our focus on rewarding our mechanics, while we work to shield our Employees and Customers from unnecessary disruptions within the operation.”

The airline and the union are meeting again March 12-14 to discuss a new contract. Southwest wants the union to pay for maintenance the airline says it has hired other firms to do.

Dunn says, “This could literally be millions of dollars so this is a very high stakes game of poker.”

The union isn’t commenting on the lawsuit publicly or in court yet.

But union leaders have previously said contract negotiations have nothing to do with maintenance write ups and that their top priority is safety.

In January, CBS News reported some mechanics felt pressured by the airline to return aircraft to service faster.

The union says the mechanics may now feel at ease to write up safety issues.

Whenever there are labor issues between an airline and mechanics, the FAA steps up its oversight of maintenance. An agency spokesman says the FAA is continuing its heightened oversight that was already in place.

Dunn says, “Surely if the union can show that these are truly safety concerns that involve passenger safety and that they’re just doing that job their job, the union could defeat the lawsuit.”

Follow Jack on Twitter & Facebook: @cbs11jack