SPANISH AIR TRAFFIC controllers have begun returning to work after engaging in a wildcat strike.

Workers began returning to their posts after the government declared a state of emergency today and threatened prosecution, according to the AFP.

Hundreds of thousands of passengers have been stranded in Spanish airports since the strikes began yesterday.

Half of Spain’s airspace has reopened, according to airport authority AENA, but it could take up to 48 hours for traffic to return to normal.

Ryanair cancelled all of its flights to and from all Spanish airports, including the Canary Islands, and Portuguese airports today. The airline said on its site earlier it expected to begin operating again tomorrow morning, but will update its notification at 7.30pm this evening.

Aer Lingus is urging its passengers travelling to or from Spain today to check the status of their flight for details of delays and cancellations.

The government called in military personnel to run the air traffic control system after civilian controllers called in sick en masse in a protest over changes to their employment conditions. Interior minister Alfredo Perez Rubalcaba told reporters that the government agreed to call a state of emergency because almost all of the country’s airports were crippled by the strike action, according to Reuters.

Rubalcaba said the measures meant controllers could be prosecuted for “committing a crime of disobedience stipulated in the military penal code”.