The Air Transport Users Council (AUC), which aims to look after passengers' interests, reported that some charter airlines operated over 25 per cent of their summer 1997 flights more than an hour late.
Such delays were "unacceptable" said Ian Hamer, the council's chairman, and he admonished poor-performing airlines - saying they must "do better".
Of charter flights monitored in summer 1997, 18 per cent were more than an hour late either arriving at or departing from nine UK airports. The average delay was 38 minutes - a considerable addition to a flight which may only last a few hours.
What is worse is for travellers is the increasing length of the delays. In the summer months of 1996, 16 per cent of flights were more than an hour late and the average delay was 35 minutes.
Among those who fared badly were many household names. A quarter of Caledonian Airways flights ran an hour late. Only fractionally better were Airtours and Air 2000. More than 20 per cent of their summer flights departed more than 60 minutes after their scheduled slots.
Airtours' average delay was 46 minutes, compared with 39 minutes in summer 1996. Air 2000 had a 39-minute average delay compared with 22 minutes the previous summer.
Rick Conley, chief executive of Caledonian Airways - which carried 1.5 million passengers last year - said that "changes have been put in place since last year". The airline will also have an extra four aircraft to deal with the extra demand this summer.
The title of "worst-performing carrier" last summer went to Nordic European Airlines. Travellers faced an average delay of 86 minutes. More than one in three of its flights was more than an hour late.
Best performer was Pegasus with just 5 per cent of flights more than one hour late and average delays of 14 minutes.
The AUC says that the league tables encourage operators to improve performance. Mr Hamer singled out Monarch as one of the few carriers to reduce delays compared with summer 1996. "Monarch has shown what airlines can do and we are now looking to those carriers that are propping up the bottom of the [delays] table to improve their service to their passengers," he said.
The figures relate to statistics collected on flights at Heathrow, Gatwick, Stansted, Birmingham, Edinburgh, Glasgow, Luton, Manchester, and Newcastle airports.
Nordic European Airlines Travellers faced average delay of 86 minutes. More than one in threee flights were late
Caledonian Airways A quarter of flights ran an hour late
Airtours and Air 2000 More than 20 per cent an hour lateReuse content