Consumer group Which? is calling for automatic compensation to be introduced for long flight delays.

The demand came as the organisation revealed that about 1.3 million passenger journeys were delayed by at least three hours last year, according to analysis of Civil Aviation Authority data.

The bulk of the delays in the year to June were with easyJet (2,618 flights) Ryanair (1,868 flights) and British Airways (1,668 flights).

The three airlines had delay rates close to the industry average of 0.7% of total flights.

But the high volume of passengers they carried still meant that more than 630,000 passenger journeys were severely delayed. Which? calculated this by using an estimated average of 102 passengers per flight.

More than 13,000 flights flying to or from UK airports were delayed by at least three hours in the past year.

Norwegian, Thomas Cook and Tui had the highest percentage of severe long-haul flight delays. Combined, the number of passenger journeys which experienced a severe delay totalled more than 38,000 across the three airlines, according to the analysis.

Thomas Cook, Tui and Saudi Arabian Airlines had the highest proportion of severely delayed medium-haul flights – across the three airlines that equated to about 40,200 passengers held up by three hours or more.

Icelandair, Aurigny and Tui had the highest proportion of severely delayed short-haul flights. The Icelandic flag carrier has seen a three-and-a-half-fold increase in the proportion of three-hour delays in the past year.

Which? said it is time for airlines to start automatically compensating eligible passengers for delayed and cancelled flights, as the current process can be complicated and time consuming.

Which? managing director of home products and services, Alex Neill, said: “Severe delays can be a complete nightmare and totally wreck a long awaited trip abroad, especially if it means you’re stuck in an airport terminal for hours on end.

“Passengers are often entitled to compensation when airlines get it wrong and it is vital that automatic compensation is introduced across the industry so that people no longer have to jump through hoops to get what they are owed.”