British Airways cabin crew who voted to strike in a dispute over job losses and changes to working practices have questioned the tactics of the Unite union.
The news comes as a High Court judge is expected to decide later today whether to allow BA an injunction against the planned strike by cabin crew.
The 12-day strike over Christmas is more drastic than cabin crew had expected, with many staff believing they were voting to walk out for only three days at a time, and starting in January, reports the Independent.
Union leaders waited until they had secured a 92% majority for industrial action before announcing when and for how long the strike would be held, it said.
"Twelve days over the Christmas period was a step too far," wrote one union member in an internet chat room accessible only to members of the British Airlines Stewards and Stewardesses Association, a section of the Unite trade union.
"I certainly wasn't aware that in voting to strike it would be 12 days and have to say I was shocked. I will of course fulfil my decision to strike but I feel physically sick at the thought."
Union leaders argued that if the strike had been held in January, British Airways management would have toughed it out without negotiating, the Independent reports.
The news comes a day after the prime minister urged BA and its staff to sit down and negotiate a settlement to the dispute.
On Tuesday, it emerged that BA was planning to take Unite to court to seek an injunction against the strikes, which are due to start on 22 December.