The developments came after BA reduced the number of cabin crew on long-haul flights from 15 to 14 in November and introduced a two-year pay freeze. The Unite union said this would hit passenger service as well as the earnings and career prospects of cabin crew.
According to BBC reports, the airline has also proposed new contracts for fresh recruits and newly-promoted staff. These include a single on-board management grade, no seniority, promotion on merit and pay set at market rate plus 10%.
But BA's chief executive, Willie Walsh (pictured), said he is "extremely disappointed" Unite is planning "massive disruption" for hundreds of thousands of customers. He said a strike would be unjustified.
In a statement a BA spokesman said: "Unite's cynical decision betrays a total lack of concern for our customers, our business and other employees within British Airways.
"Thousands of staff across the company have made contributions to the cost reductions that are essential to move the company back toward profitability. Our cabin crew, who are rightly renowned for their professionalism and skills, cannot be exempt from this process.
"Our package for them is very fair and reasonable. It reduces no one's terms and conditions, and gives most crew pay rises of between 2% and 7% this year and next year. British Airways' cabin crew are already the best rewarded in the UK airline industry."
According to BA the company discussed changes to packages with staff for nine months and are largely based on meeting voluntary applications for part-time working and redundancy.
The statement continued: "We have made clear to Unite that we want them to talk to us about their ideas for the recruitment of new crew in future when the business is in a position to grow. That invitation remains open."
Walsh added: "A strike is senseless - and we urge Unite to draw back. We will not be reversing our changes to on-board crew numbers. They have allowed us to accept more than 1,000 requests for voluntary redundancy - and those former colleagues have left the business.
"Unite must understand there can be no return to the old, inefficient ways if we want to ensure long-term survival in the interests of our customers, shareholders and all our staff.
"They have no justification for threatening such extreme action. It is very sad that they are seeking to use the Christmas holiday plans and family reunions of hundreds of thousands of people to try to pursue their case."