The Times reports that about 150,000 passengers will have their flights cancelled next week, during the first of British Airways (BA's) planned series of strikes that will ground flights between May 18 and 23.
There will then be a single day's pause before the second round of strikes on May 24 to 28, and further walkouts on May 30 to June 3 and June 5 to 9.
Willie Walsh emailed executive club members yesterday, referring to Unite's actions as "callous":
"..As you are undoubtedly aware, Unite, the trade union that represents British Airways' cabin crew has announced further strike action.
I wanted to update you on the situation and thank you for your continued loyalty and support.
We were saddened but not surprised that Unite has announced plans for strikes that span 23 days including the May bank holiday and half term. I can assure you that this action will not ground British Airways.
Unite officials continue to show a callous disregard for our customers. A small minority act as if they want to destroy BA and the jobs of thousands of their colleagues. And just when the UK economy needs help to get back on its feet, Unite will deal it another blow.
The offer on the table is very fair. It includes a guaranteed pay rise for the next two years, meets the union's concerns on crewing levels, access to routes and maintains a standard of living that reflects the value and service our cabin crew deliver to our customers.
During the last two periods of industrial action, thousands of staff from across the airline, including volunteers, kept British Airways flying and we flew more than half a million customers to their destinations.
We are confident that many cabin crew will again ignore Unite's pointless strike call and support the efforts of the rest of the airline.
On the strike dates we will operate all London Gatwick and London City services. At Heathrow we plan to operate a substantial part of our longhaul schedule. There will also be a number of daily flights to every destination across our shorthaul network.
We are talking to other airlines about leasing in extra aircraft to support our shorthaul schedule and we will buy thousands of seats from other airlines to help our customers rebook if their original flight is cancelled.
I fully appreciate that information is critical during such a period so we will regularly update ba.com with details of our revised schedule and options available.
Your support, patience and understanding during the recent months have been invaluable and I would like to thank you in advance for your continued loyalty in support of our business..."