Thomas Cook pilots will go ahead and stage three more strikes this Autumn if disputes over pay is not resolved, says the British Airline Pilots' Association (Balpa).
This follows their 12-hour walkout which started at 3am today, 8 September - the first strike by UK pilots since 1974.
The walkouts would take place on 23 and 29 September and 3 October unless there is a positive outcome from talks with conciliation and grievances service, Acas.
Thomas Cook has cancelled all bookings to Sharm el Sheikh until October 31.
The holiday company took the decision to extend the ban - past May 25 -after travel advice from the Foreign & Commonwealth Office did not change.
The FCO has advised against all but essential travel to the resort.
Flights to the resort had been leaving from Bristol Airport.
Thomas Cook is now offering a number of options to their customers, which include cancelling or amending their holiday to another destination free of charge.
They have increased staff numbers in their contact centre to help deal with queries.
Any customers with immediate concerns and who unable to visit a shop should call the dedicated customer phone line, open 24 hours a day: 01733 224 536.
Click here for the full and most recent FCO travel advice.
There are further delays for passengers at Bristol Airport as their plane will now take off over an hour later than planned.
264 passengers are still in Bristol after their flights to Ibiza and Palma were cancelled yesterday. A flight was originally scheduled for 4pm this afternoon, but has now been delayed until 5:15.
264 passengers are waiting to fly to Ibiza and Palma after Thomas Cook flights were delayed.
More tourists were taken to Manchester by bus to fly from there, but the 264 remaining passengers spent the night at the Mercure Hotel in Bristol and are still waiting to fly. 145 will fly to Ibiza at 4pm this afternoon, and a further 119 will travel to Palma on the same flight.
Several representatives from Thomas Cook Airlines are meeting passengers at Bristol Airport to offer an 'unreserved apology' and discuss their entitlement to refunds and compensation.
Bristol Airport say two flights have been delayed. One plane was due to leave for Ibiza at 0600 yesterday, the other for Palma at 0645.
97 passengers for Ibiza and 54 for Palma went to Manchester by coach and flew from there. The remainder will be put on a flight from Bristol at 1600, first to Ibiza and then to Palma.
Reports are coming in that hundreds of passengers have been forced to spend the night in Bristol after delays to Thomas Cook flights to Ibiza.
Some travellers have tweeted that they had to spend 7 hours at the airport before being taken to the Mercure Hotel in the city for the night. They claim staff shortages were to blame. So far Thomas Cook have not been available for comment.