Holiday plans for thousands could be thrown into chaos after pilots from Virgin Atlantic agreed to ballot for a strike in July.

The planned action by up to 750 pilots will hit long-haul routes during the school summer holidays.

The pilots, who earn between £58,000 and £110,000 a year, are angry at a 4 percent offer made to them by Virgin Atlantic following three years of pay freezes, according to their union, the British Airline Pilots’ Association.

The ballot will start on May 24 and take four weeks to complete on June 21. BALPA will then have to give a week’s notice of any industrial action, which union leaders say could take place in July.

The decision comes just days after union leaders at British Airways said they had agreed a deal with the airline over its long-running cabin crew dispute, which is now subject to a ballot with union backing. That deal appears to have ended the threat of a further strike action by BA over the summer.

BALPA General secretary Jim McAuslan said: “Pilots in Virgin have not had a pay increase since 2008.”

“During the tough years pilots have made sacrifices to help the business on the basis that fair pay would return, but that hasn’t proved to be the case.”

“The company is offering pilots an increase this year of 4%, with 3% next year and 3% in 2013.”

“The 4% does not reflect the fact that pilots have not had a rise since 2008, and the proposed 3% increases would mean that with inflation running at 5% and likely to remain high, pilots would, if they accepted these increases, be in effect voting themselves years of wage cuts.”

He added: “We do not want a dispute but to date there has been no meaningful movement by the company and even the involvement of Acas has not broken the logjam.”

“With nowhere left to go we have been left with no alternative but to give Virgin management notice of a ballot of Virgin Atlantic pilots for industrial action.”

A spokesman for Virgin Atlantic said: “The company has made a fair, affordable and sustainable offer that is in line with the rest of the industry and we continue to be open to dialogue.”