The Virgin Atlantic ballot is one of two called by the Unite union

Staff say they are underpaid compared with some of Virgin's rivals. It would be the airline's first-ever strike.

The ballot will run for three weeks with a result shortly afterwards.

Virgin Atlantic says it is disappointed the ballot is taking place, and that its two-year offer is the best in the airline industry in 2007.

Virgin proposes to raise salaries by 4.8% in the first year, and retail price inflation in the second year.

"We would hope that the cabin crew who are union members would not do anything to affect our leading reputation for customer service," a Virgin Atlantic spokesman said.

Two ballots

Virgin Atlantic cabin crew flying on business routes claim they earn thousands less than crew members at British Airways who are doing a similar job.

Any strike would take place in January and could add to months of possible frustration for travellers.

That is because Unite's 5,000 BAA workers at airports such as Heathrow and Gatwick are also being balloted on strike action, over a proposal to stop new staff joining the airport operator's final salary pension scheme.

BAA owns Heathrow, Gatwick, Stansted, Southampton, Glasgow, Edinburgh and Aberdeen airports.

Unite is to run its two ballots - at BAA and Virgin - in parallel, with the closing date for both being 20 December.

A BAA strike could see airports closed from 27 December, leading to chaos during the New Year travel period.

Virgin Atlantic is 51% owned by Richard Branson's Virgin Group and 49% by Singapore Airlines, which bought its stake in the airline in 1999 for �600m.

It operates long-haul flights from the UK to the US, the Caribbean, Asia, the Middle East and Africa.