PHOENIX - US Airways mechanics won't accept a 3 percent raise followed by another 2 percent in 18 months, and say the airline is disrespecting them as it works towards its merger with American Airlines.

The union representing the mechanics, the International Association of Machinists Local 142, has been negotiating a new contract with the airline for two years, and officials said their deal was put on the backburner once the airline announced its $11 billion deal with American on Feb. 14.

The 3,500 US Airways mechanics and related workers are scheduled for a raise this July of 3 percent if they don't get a new contract, but that won't suffice, union president Tom Higginbotham said. More than 630 of those employees are based in Phoenix. An additional 34 members of the union who work in maintenance for the airline negotiate separately for contracts.

In a letter to members, the union said that during meetings last week in Washington, D.C., US Airways offered to move the date of the expected 3 percent raise up from July to whenever the new contract is signed and added another 2 percent in 18 months.

"The company's position on premiums, pension contributions, and other economic proposals were inadequate," the note said. "These proposals were a slap in the face to this membership, and flatly rejected by your (negotiating) committee."

A spokesman for the airline said the negotiations are ongoing.