The accusations come as airports are coping with one of the busiest periods of the year, with thousands of people expected to leave Britain for the bank holiday weekend as well as those starting or returning from their summer holidays.
However, the Federation of Tour Operators said that flight times were the responsibility of a number of scheduling committees and that "99 per cent of holidaymakers get a good deal".
Bob Tolliday, project manager for the association's Holiday Which? magazine, said yesterday that travel firms were running "vastly over-optimistic" programmes which took no account of delays in Europe.
"People are suffering terrible delays, their holidays are being ruined and they are not getting the compensation they deserve," Mr Tolliday said.
"I have one message for people flying off for the bank holiday weekend - expect delays. Airlines must not make empty promises about flight times. Air-traffic delays in Europe are becoming an increasing problem yet there is an amazing amount of tight scheduling by airlines," he added.
"Tour operators and charter airlines should get more realistic about how long flights take. They should not make promises they can't keep."
This weekend is the busiest for Gatwick, Britain's biggest holiday airport, which was yesterday preparing to cater for 370,000 passengers over four days. Saturday is expected to be busiest, with an estimated 102,000 people passing through. The airport in West Sussex experienced lengthy delays and a passenger revolt early in the week. More details emerged yesterday of a sit-in by 50 passengers who arrived there last Monday after their flight from Malaga in Spain was delayed more than 11 hours.
The irate group, who claimed not to have received any refreshment or accommodation at Malaga, was eventually pacified by promises of a one- off pounds 100 payment from Goldcrest, the aircraft leasing company.
Goldcrest, part of the Inspirations travel group, warned that the pounds 100 payment was very much a one-off thing and that another time police might be called to clear the aircraft of protestors.
The Air Transport Users Council said that calling the police might be described as "a bit heavy", while Mr Tolliday wondered whether such a policy was really the best way of dealing with the situation.
Alan Flook, general secretary of the Federation of Tour Operators, said that flight times were the responsibility of various scheduling committees.
"Brochures are often out before schedules are finalised. Generally, 99 per cent of holidaymakers get a good deal, but it's always the delays that make the news," Mr Flook said.
"The situation at Gatwick last week was horrific - the worst since the late Eighties. It should not have happened. It's up to tour operators to look after delayed holidaymakers to the best of their ability. I would agree that there are times when the compensation paid out is not enough."Reuse content