Virgin Atlantic pilots have voted by a massive 97% to go on strike in a row over pay, raising the threat of summer walkouts which would cause travel chaos.
The British Airline Pilots Association (Balpa) said there was a 94% turnout in a ballot, called in protest at a 4% pay offer.
The union held back from naming strike dates, but warned that the size of the vote sent a "clear message" to the airline's boss Sir Richard Branson.
General secretary Jim McAuslan said it was the first time Virgin pilots had voted to take industrial action, adding that he was happy to meet Sir Richard any time, anywhere, to try to head off strikes,
"My messages are simple - pilots do not want to strike and are hugely disappointed by the company's approach. There has been no UK pilot strike for 32 years, but there comes a time when even moderate people say 'Enough'.
"Pilots are being driven to strike. With no pay increase since 2008, a below-inflation offer for 2011 and proposals for 2012 and 2013 that will be sub-inflation, this is now a six-year attack on living standards which has not happened in any other UK airline.
"Pilots are prepared to strike. We have absolute resolve to secure a fair settlement. When a group of professional people say 'Enough', someone at the top should sit up and listen. We do not want to inconvenience the public and hope that Sir Richard will use some of his undoubted Virgin flair to settle this.
"Having been at this since last November, time is running out. If damage is to be avoided and passengers not inconvenienced, then Sir Richard needs to act now."
The union said Virgin Atlantic pilots have not had a pay rise since 2008 after agreeing to forgo an increase to help the company, with the expectation of a "fair" hike this year.
Balpa, which represents most of Virgin's 750 pilots, said it decided to ballot its members because it had expected a bigger pay deal this year.
Bob Atkinson, of online comparison service travelsupermarket.com, said: "We are disappointed and frustrated that customers of Virgin Atlantic face the potential of strike action in the coming weeks.
"The last thing that any holidaymaker or business traveller needs is uncertainty over their travel plans and the threat of flight cancellations. Disruption as we head into the busy summer months is bad news for consumers.
"We advise that all passengers booked with the airline or on package holidays using the carrier, ensure the airline and/or their tour operator has the most up to date contact information for them on record. They can then be informed if and when any action takes place.
"We call on both Virgin Atlantic and the union to get back around the table and ensure that hard earned holidays and flights for business travellers are not disrupted."