Leaders of British Airways cabin crew will next week consider calling fresh strikes after the rejection of a deal aimed at ending their long-running dispute.
Members of Unite voted by 81%, in a 71% turnout, not to accept a proposal from the airline which would have ended a bitter, year-long row which has already led to industrial action.
Union activists will press their leaders to call a lengthy strike following a series of stoppages in March which caused travel chaos for passengers and cost BA tens of millions of pounds.
BA accused Unite of "orchestrating" rejection of a "very fair" offer it said addressed all the concerns raised during 14 months of talks.
Representatives of the cabin crew will meet Unite's joint general secretaries, Derek Simpson and Tony Woodley, on Monday to discuss their next move.
The two union leaders said today: "BA management should take note of their own employees' strong rejection of their offer and immediately address the outstanding concerns.
"They should make no mistake that Unite is fully committed to supporting our members in furthering this dispute if no resolution is found."
BA said in a statement: "British Airways is disappointed but not surprised that Unite has clearly orchestrated a rejection of a very fair offer that addresses all the concerns raised during 14 months of talks.
"We urge Unite to put an end to this unnecessary dispute and focus on the best interests of its members. There can be nothing positive to be gained from further strikes.
"The majority of our crew came to work during the previous strikes and demonstrated their firm commitment to our customers, despite their union's callous disregard for the travelling public.
"Unlike other businesses and airlines, we have avoided compulsory redundancies. Cabin crew face no pay cut or reduction in terms and conditions, and remain the best rewarded in the UK airline industry.
"It is not too late for Unite to put an end to this dispute and support our recovery from two consecutive years of record losses and return to sustained profitability and job security for its members."
The dispute was inflamed yesterday when a union official representing cabin crew was sacked, the fifth Unite member to be dismissed as a result of the dispute.
Unite had urged members to reject the proposed deal as BA had not fully restored travel concessions taken away from those who went on strike and because more than 50 union members have been suspended.
The two sides have been in dispute for more than a year in a row over jobs, pay and working practices, including staffing levels on aircraft.
The main sticking points now are linked to the strike in March, when thousands of cabin crew walked out, forcing BA to put in place contingency plans to keep aircraft flying.
Unite will have to give a week's notice of any fresh strikes.
Peter Smith, flights expert at travelsupermarket.com, said: "2010 is turning into an annus horribilis for British travellers as a chain of events have caused disruption to travel plans, while BA customers' loyalty is being tested to the extreme as they face yet more problems caused by industrial action.
"Strike action would not only be a disaster for BA customers, but also for the airline itself. Having already lost millions during the recent ash disruption, the airline can simply not afford to let this dispute rumble on any longer.
"There needs to be an end to the customer misery to allow the Great British travelling public to regain confidence in the airline and to travel without disruption.
"The longer this dispute goes on, the more likely it will be that customers will turn their backs on BA and look to travel with alternative carriers where they can."