A U.S. District Court judge ruled in favor of a move by

Northwest Airlines

(NWACQ)

to impose contract terms on its flight attendants and issued a temporary injunction to keep them from striking.

Judge Victor Marrero concluded that a strike would hurt the traveling public and could seriously harm the fifth-largest airline, which is reorganizing in bankruptcy court.

Marrero said Friday that the Association of Flight Attendants hadn't completed the procedure that labor law requires before a strike can occur because it wasn't formally released from mediation. The union represents Northwest's 9,000 flight attendants.

He also said that Northwest has "demonstrated at least fair ground for further litigation of its claim, if not a likelihood of success on the merits." Marrero said that in light of Northwest's "prospects for reorganization and the impact on the traveling public, the hardships tip decidedly in favor of Northwest."

He referred the case back to U.S. Bankruptcy Court Judge Allan Gropper, who ruled last month that flight attendants had the right to strike. However, at the time, he said he lacked the jurisdiction to issue an injunction preventing a work stoppage, and he encouraged an appeal. Marrero said Gropper does in fact have jurisdiction.

While the airline applauded the decision, the union said it will appeal. "We believe this decision is obviously an incorrect reading of the law and the rights of workers in the United States," said David Borer, AFA general counsel.

The legal battle between Northwest and its flight attendants has centered on the question of whether labor law or bankruptcy law takes precedence. Despite a series of airline bankruptcies since 2002, the question hasn't been formally resolved because both management and labor had previously been unwilling to push the issue to a strike that could force an airline's shutdown.

But in the case of the Northwest flight attendants, union members twice rejected tentative contract agreements aimed at paring annual costs by $195 million.

Bankruptcy law is intended to allow financially troubled companies to reorganize by shedding obligations, including collective bargaining agreements that impede their ability to continue operating. The Railway Labor Act, which governs airline labor relations, presumes that strikes can occur, but establishes a methodology to resolve disputes before they get to that point.