The machinists union is opposing Hawker Beechcraft’s efforts to enter into exclusive talks with a Chinese firm for the sale of its civilian aircraft operations.

A motion filed Monday in U.S. bankruptcy court in New York asks the judge to deny a request seeking up to 45 days to negotiate with Superior Aviation Beijing Co., for the sale of the Kansas manufacturer for $1.79 billion. Superior has agreed to pay $50 million during the exclusivity period to cover operating costs for the business jet company while the deal is finalized.

The union contends the proposed sale to a Chinese government-backed entity has implications for the U.S. economy and national security. It also objects because Superior would not assume pension obligations.

Hawker Beechcraft says it would issue a statement later.