British Airways cancelled around 1,300 flights next week after a breakdown in talks with its largest union pointed to a threatened 48 hour strike by cabin crew going ahead.
Cancellations would affect more than 140,000 passengers and involve most flights to and from London's Heathrow and Gatwick airports, with further disruption before and afterwards.
"The airline remains committed to pursuit of a negotiated settlement before next Tuesday but wants customers to have early warning of its flying schedule," BA said in a statement.
The Transport and General Workers' Union (T&G) has threatened two further 72 hour strikes in February unless there is agreement on issues which include sick-leave policy and pay.
The union says 96 percent of the cabin crew it represents are in favor of strikes.
"If it (T&G) is serious about solving this dispute peacefully it should turn away from confrontation and support our approach to (conciliators) ACAS in a bid to find a breakthrough," BA Chief Executive Willie Walsh said in the company's statement.
Walsh took the helm of Europe's third-largest airline in October 2005 vowing to make it more efficient, key to making a success of BA's move in March 2008 to a new terminal at Heathrow.
BA says cabin crew were taking an average of 22 sick days per year before Walsh took charge and that under a new absence policy the figure has fallen to 12 days.
This week, Walsh called on ACAS -- the publicly-funded, independent Advisory, Conciliation and Arbitration Service (ACAS) -- to help resolve the dispute with the T&G.
Some 10,500 of BA's approximately 15,000 cabin crew are members of the T&G, forcing the airline into a difficult position to sustain operations.
The airline warned that if strikes take place, there will be further disruption of flights both before and after each walkout.
"British Airways' flight program is complex, involving the combination of rosters for 15,000 cabin crew, 3,000 pilots and 234 aircraft," it said. "More than 8,000 crew have to be in the right place at the right time."
It said flights which are expected to fly as normal include some longhaul flights into Heathrow and some into and out of Gatwick. Its Manchester to New York JFK daily service will also operate as normal.
Other flights which are not expected to be affected include those on subsidiary BA Connect, on franchise partners GB Airways, BMED, Loganair and Sun Air, and those flown by other carriers such using a BA code share flight number.