Easter holiday makers face the threat of flight chaos with BA pilots considering strike action.

The pilots, through their union the British Airline Pilots' Association (BALPA), accuse the airline of trying to downgrade pay and conditions by stealth.

BALPA general secretary Jim McAuslan said BA was employing less skilled and lower paid pilots for its OpenSkies subsidiary to fly between Europe and the United States from June.

"Then the company will use this poorer paid pilot force as a Trojan horse to beat down the pay and conditions of its current pilot employees," Mr McAuslan said.

"We have seen the evidence and what BA proposes is an attack on current pilots and their families.

"That is why we are vigorously opposing this outsourcing. OpenSkies will be using BA planes and they should be crewed by BA pilots."

The association is balloting BA pilots on industrial action.

A BA spokesman said the company was not trying to drive down conditions.

"We have guaranteed to BA pilots that the creation of OpenSkies will not in any way affect their current or future terms and conditions," the spokesman said.

"It is simply not true that the new subsidiary will be used to beat down' BA pilots' pay and conditions or threaten their jobs.

"BALPA's fear are unfounded. British Airways will not use OpenSkies as a Trojan horse'.

"Our growth plans for BA at Heathrow and Gatwick mean we will be creating 300 extra pilots' jobs over the next two years."

OpenSkies is due to take off in June with one Boeing 757 aircraft flying from New York to either Brussels or Paris Charles de Gaulle airports.

A second aircraft will be added later this year to fly to other European cities.

BA chief executive Willie Walsh said the plan was to operate six 757s by the end of 2009, all of which will be sourced from the current British Airways' fleet.

The ballot closes on February 20.