Spain said it would declare a state of emergency if air traffic controllers did not end a wildcat strike which paralyzed air traffic for a second day on Saturday, threatening to deepen the country's economic problems. "If the situation doesn't normalize, the government will declare a state of emergency," Deputy Prime Minister Alfredo Rubalcaba said ahead of a hastily assembled cabinet meeting in Madrid. "The controllers will be mobilized and if they don't get back to work, their cases will be passed immediately to the judiciary and they will be accused of a crime which could mean a prison sentence." The Spanish army took over air control towers on Friday afternoon after unofficial strike action by controllers grounded planes and disrupted travel for around 250,000 people on one of Spain's busiest holiday weekends. The walkout by the air traffic controllers, who are locked in a long-running dispute over pay and conditions with the state-run airport authority AENA, quickly stopped flights in and out of Spain's main airports. The unofficial action followed cabinet approval of changes to rules on the number of hours air traffic controllers can work per year and of a law allowing the army to take over air space in times of emergency. The government has also approved plans to sell off 49 percent of AENA, a move unions have condemned. The controllers gave no warning before starting their walkout by claiming sick leave and leaving their posts, effectively closing the whole of Spanish airspace except the southern region of Andalucia. The air traffic controllers' union, USCA, said its workers were not on strike but had had enough. "This is a popular revolt," USCA head Camilo Cela told. Flag carrier Iberia canceled all its flights from Spain until 1000 GMT on Saturday. Vueling also said it was cancelling flights. Some international flights landed at Madrid's Barajas airport overnight, local media reported. AENA said on its website that Spanish airspace would remain closed until 1200 GMT on Saturday. The airport authority recommended travelers avoid its airports and contact their operators for information. "I was inside the plane with my kid and they told us the plane was not flying as controllers had decided to strike..." Ramon, a Madrid resident who was flying to Mallorca for his mother's funeral, told. Spain is carrying out tough reforms and spending cuts to rein in its deficit, kickstart its sluggish economy and ward off market fears it may need a bailout similar to that of Ireland.