An estimated 1.3 million air passenger journeys were subject to a severe delay (at least three hours) in the year to June 2018.

According to analysis of Civil Aviation Authority (CAA) punctuality data by campaign group Which?, this meant more than 13,000 flights to or from UK airports were delayed – the equivalent of nearly 3,500 passenger journeys a day.

Norwegian experienced the highest number (2.4%), followed closely by Thomas Cook (1.8%), and TUI (1.6%) for long-haul flights.

For medium-haul flights, Thomas Cook had the most (1.2%), TUI came second (1.1%) and Saudi Arabian Airlines (1%) came in third. For TUI and Thomas Cook, this impacted around 38,000 passenger journeys.

On short-haul flights, Icelandair (1.7%), Aurigny (1.6%) and TUI (1.4%) experienced the highest proportion of severely delayed journeys. Which? said Icelandair has seen a three and a half-fold increase in the proportion of three-hour delays in the last year.

A significant contributor in this category came from budget airlines Easyjet (2,618), Ryanair (1,868) and British Airways (1,668).

Flight delay compensation

Under current EU regulations, passengers are entitled to compensation if delayed by more than three hours when flying from the UK or with an EU airline to an EU airport.

Flyers are entitled to between £220 and £360 compensation on short-haul flights, and up to £535 for longer flights, depending on the length of delay and exchange rate.

Airlines are only exempt from paying out if they can prove that the delay or cancellation was caused by ‘extraordinary circumstances’ such as extreme weather conditions or airport strikes.

But according to the CAA, industrial action taken by an airline’s own employees, such as the Ryanair pilot strikes that took place last month, does not count as an extraordinary circumstance and passengers can claim compensation if a flight is severely delayed or cancelled for this reason.

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

This can lead to flyers turning to claims management companies, meaning they may have to hand over up to 40% of the pay out.

Alex Neill, Which? managing director of home products and services, 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. 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.”