FORT WORTH, Texas (CBSDFW.COM/AP) — American Airlines accuses its mechanics and their unions of conducting an illegal work slowdown to gain leverage in contract talks, and the airline is asking a federal judge to stop the activity.

The airline says mechanics have caused about 900 cancellations or long delays since early February by taking an unusually long time to repair planes and refusing to work overtime.

An American Airlines Boeing 737 Max 8 is seen as it pulls into Miami International Airport. (credit: Joe Raedle/Getty Images)

On Monday, American filed a lawsuit in federal district court in Fort Worth against the Transport Workers Union and the International Association of Machinists and Aerospace Workers, which together represent American’s aircraft mechanics.

American says the slowdown will affect 3,400 passengers a day if it continues into summer.

The Transport Workers had no immediate comment. The IAM did not immediately respond to a request for comment.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)