The country’s largest carrier is planning to increase the 70 per cent of flights which took off during the last seven days of strikes.

It’s promising that a "substantial number" of flights will continue to operate from Heathrow, with Gatwick operating a full schedule.

Cabin crew union Unite has ordered four strikes, each of five days - May 18 to 22 and May 24 to 28, May 30 to June 3 and June 5 to 9.

The union has refused to rule out further stoppages if the dispute over pay, jobs and working conditions is not settled.

BA chief executive Willie Walsh is maintaining a hard line and refusing to give in to union demands, the Evening Standard newspaper reports.

He plans a raft of measures to maintain as much of the scheduled timetable as possible.

Pilots are not in the dispute and will work as normal.

Jim McAuslan, leader of the British Airline Pilots’ Association, said they would "ensure that a professional service is maintained".

BA is negotiating to hire up to 25 aircraft a day from rival carriers and has more than 1,000 trained substitute cabin crew - volunteers from other parts of the company - on standby.

Travellers due to fly next week will learn later today or tomorrow if their flights are affected.

About 80,000 travellers a day use Heathrow on 550 flights — 150 long-haul and 400 short-haul.

Unite said it was ready to call off the strikes if BA entered "meaningful negotiations".

But the parties remain deadlocked over issues including BA’s refusal to rescind the lifetime ban on concessionary travel for cabin crew who took part in the last round of strikes.