Spanish union leaders are threatening to unleash a strike by airport workers that could close down Spain's hubs during the busy Easter vacation season.

The General Workers union and the Workers Commission union say negotiations with the government over its plans to partly privatize the civil aviation agency AENA have broken down.

GWU representative Raul Gomez said Saturday that "the strike would affect all airports" in the country.

Spain's Socialist government halted an air traffic control strike in December by imposing an emergency decree that threatened employees with prison and placed control towers under military supervision.

AENA director Javier Marin said he was confident that a strike-averting deal could still be achieved.