Air travel in Spain has been severely disrupted by a strike by workers of the national airline, Iberia. More than 400 domestic and international flights have been cancelled because of the protest over cabin crew wages. The stoppage is planned to run through today and tomorrow.Unions representing more than 4,000 staff say cabin crew pay has not risen in four years, while the salaries of other employees, including pilots, have increased during the same period. Iberia is struggling to cope in the global recession and its plans for deeper cooperation with other leading airlines has come under close scrutiny at the European Commission. The Financial Times is reporting that Brussels has warned the Spanish company, American Airlines and British Airways that their proposed deal on transatlantic flights might come at cost. Regulators say they may have to give up some take-off and landing slots.