Spain’s airport strikes, threatened for over the Easter holiday, will force Ryanair to cancel 300 flights for 57,000 passengers unless the action can be averted.

The airline’s boss Michael O’Leary, speaking during a visit to Madrid, called on the EU to strip airport staff of the right to strike.

He said: “It’s unacceptable that Spanish airport workers with their selfish strikes can hold an entire country to ransom.”

Spain’s airports to close over Easter – travel chaos looms

Meanwhile, those planning holidays to Spain over Easter have been warned that only insurance booked before the strike action was called, would cover cancelled flights.

Three unions representing 12,500 ground staff employed by Spanish airports authority AENA are behind the threats.

They plan to call walkouts on April 20, 21, 24, 25 and 30; this year, Good Friday falls on April 22. More strikes have been set for May, June and July.

Spain’s baggage handlers and fire crews would be among those expected to answer the strike call, which could bring many airports to a virtual standstill.

Raul Gomez Alonso, of Spain’s General Union of Workers, insisted: “The government, not the workers, are to blame for what’s going to happen.”

Spain was gearing up for a bumper tourist season after two bad years. Worried AENA president Juan Ignacio Lerma admitted: “A strike is the worst scenario. We will do everything we can to avoid it.

“A strike would seriously damage the tourist sector at a time when the outlook for Easter and summer are very encouraging. I urge the unions to negotiate.”

Tourism is key to the Spanish economy, with the country receiving more than 44million visitors every year – 15million of them British.

The strikes will bring the country’s tourism industry to its knees.

Spain is also a major destination for bmi Baby, which links Spain to Birmingham, Manchester, East Midlands and Cardiff.

A spokesman for the airline said: “We urge the parties involved to resolve this dispute as a matter of urgency so that any disruption to our customers can be avoided.”

Travel analyst Bob Atkinson of called the action “a potential nightmare” which could affect hundreds of thousands of passengers.

He advised people heading to Spain on affected days to contact their holiday or flight providers, and warned that only holiday insurance booked before the strike dates were announced will offer protection for potential disruptions.

The strike action has come about because of the Spanish government’s plans to sell off 49 per cent of the state-run airport operator and privatise the management of Madrid and Barcelona airports.

Workers fear their jobs and working conditions will be threatened.

The Spanish government wants to use the proceeds of the sale to cut a swollen public deficit.