The organisation has called for a "major overhaul" of travel sector rules to ensure operators are held to account when they treat passengers badly.

In a new report, Which? has set out areas where it believes some airlines are "routinely ignoring" consumer rights law, following months of disruption at UK airports, flight cancellations and "brazen rule-breaking" by some airlines.

The consumer association is calling for significant reforms, including a code of conduct for airlines and new, stronger powers for the Civil Aviation Authority (CAA), so it can hit operators with heavy fines when they flout the rules.

Despite previous warnings from the CAA that excessive fees could be open to legal challenge, some airlines continue to charge a premium for admin services, such as ticket transfers, correcting names and checking in at the airport.

Which? further welcomed proposals from the government for the CAA to get stronger powers, which it said must include powers to fine airlines directly when they break the rules and to provide clarity for passengers and the industry.

It is also calling on ministers to drop plans to weaken passenger compensation rights for UK domestic flights. 

Rocio Concha, Which? director of policy and advocacy, said consumer rights and laws are "meaningless" if they are not enforced.

"Our analysis shows some airlines are routinely ignoring their legal obligations and ripping off their customers, with little fear of facing any consequences," Concha added.

"The government must take action to restore consumer confidence in travel. That should start with a consumer-focused code of conduct all airlines must adhere to, and stronger powers for the CAA, including the ability to fine operators directly when they break the rules."

A CAA spokesperson said: "We thank Which? for its continued engagement regarding contract terms and airlines. We will review its latest evidence thoroughly and will respond accordingly.

"We have regularly called for stronger consumer powers, including the ability to impose fines on airlines. This would allow us to take faster action when appropriate and bring our powers in line with other sectoral regulators."