Ryanair has been named the worst airline serving UK airports for the sixth year in a row.
An annual survey by consumer group Which? found that passengers gave the Dublin-based carrier the lowest possible rating for boarding, seat comfort, refreshments and cabin environment.
This lead to an overall customer score of just 40%.
Of those who said there was one airline with which they would never travel, more than two out of three (70%) named Ryanair.
Which? recorded 12,459 flying experiences from 7,901 of its members.
In December the Civil Aviation Authority launched enforcement action against Ryanair over its decision not to pay compensation for flight disruption resulting from industrial action by its staff during summer 2018.
The airline has also faced criticism for changing its hand luggage policy twice last year, resulting in charges for passengers flying with small wheelie suitcases.
One passenger told Which?: “There are too many rules. I worry about getting caught with hidden costs.”
The consumer group also highlighted that Ryanair made £1.75 billion last year from extras, such as assigned seating, priority boarding and luggage fees.
Other names at the bottom of the ranking for short-haul flights were Thomas Cook Airlines (52%), Wizz Air (54%), Vueling Airlines (54%) and British Airways (56%).
EasyJet came in the middle of the ranking at 63%.
The highest scores for airlines making short-haul trips were earned by Aurigny (81%), Swiss Airlines (80%) and Jet2 (75%).
A Ryanair spokeswoman said the research did not take into account the cost of fares - which is “the single most important factor for UK consumers” - and described it as “totally unrepresentative” compared with its 141 million annual passengers.
She added that the airline’s average fare of £35 is “a fraction of the high fares charged by Which’s ‘recommended’ airlines”.
Rory Boland, editor of Which? Travel magazine, said: “Airfares might seem to be getting cheaper, but only if you don’t fancy sitting with your family and children or taking even a small cabin bag on-board.
“Increasingly you need a calculator to work out what the final bill will be, especially with Ryanair.
“It has spent the last two years cancelling thousands of flights, ruining hundreds of thousands of holidays and flouting the rules on compensation as well.
“The results of our survey show passengers are fed up. They should switch to one of their rivals, who prove that budget prices don’t have to mean budget service.”
- Here are the top three airlines for short-haul flights, according to Which? research (customer score in brackets):
1. Aurigny (81%)
2. Swiss Airlines (80%)
3. Jet2 (75%)
- Here are the worst three:
1. Ryanair (40%)
2. Thomas Cook Airlines (52%)
=3. Wizz Air (54%)
=3. Vueling Airlines (54%)
- Here are the top three airlines for long-haul flights:
1. Singapore Airlines (85%)
2. Emirates (81%)
3. Qatar Airways (80%)
- Here are the worst three:
1. American Airlines (52%)
2. United Airlines (55%)
3. Thomson/Tui Airways (56%)