Pilots at British Airways will go on strike for three days in September in an ongoing dispute over pay.
The British Airline Pilots Association (BALPA) has announced that strike action is due to go ahead on September, 9, 10 and 27.
The union said it put forward a number of packages during several days of talks at the conciliation service Acas that it believed would have resolved the dispute without a strike.
However, the packages were not accepted by BA and the dispute has not been resolved.
BALPA say it has had "no choice" but to call for the strikes after a total of 93% of members voted in favour of industrial action on a 90% turnout.
However BA has criticised the industrial action as "unjustifiable".
The strike action could spell severe disruption to holidaymakers who have flights booked on the days the strike has been called.
The strike action will be held between 12.01am on September 9 and 11.59pm on September 10.
A second strike will be between 12.01am and 11.59pm on September 27.
More dates for strike action could also be announced as the dispute rumbles on.
A statement from BALPA said: "A day of strike action will cost BA around £40m. Three days will cost in the region of £120m. The gap between BA's position and BALPA’s position is about £5m. Our proposal remains on the table should BA wish to reach agreement prior to strike action.
"British Airways is an extremely profitable and successful company, and pilots have been proud to play their part in that. In 2018 the company announced profits of £2bn.
"Over recent years BA pilots have made sacrifice after sacrifice to assist the company such as taking a pay cut, productivity increases, closing the final salary pension scheme, giving up annual leave days, a new rostering system, and reducing flying pay."
In British Airways' centenary year, this will be the first time its pilots will go on strike.
BALPA added that the strike is "a last resort" and is being taken "with enormous frustration at the way the business is now being run".BA said: "It is completely unacceptable that BALPA is destroying the travel plans of tens of thousands of our customers with this unjustifiable strike action."