Campaigners are urging the UK Government to step in after a third of flights were found to have run behind schedule last year.
It comes as the Civil Aviation Authority said an "unacceptable" 37 per cent of flights were delayed by at least 15 minutes in 2022. That is up from 17 per cent in 2020 and 2021 and 25 per cent in 2019, before air travel was impacted by Covid-19.
As well as more waiting times than previous years, flights were delayed by an average of 22 minutes, which is 60 percent longer than in 2019.
Rocio Concha, Which? Director of Policy and Advocacy, said: "These dreadful performance figures will be unsurprising to anyone who endured the widespread chaos at UK airports last year.
"Which? has received hundreds of testimonies from travellers left high and dry by airlines when their flights were cancelled or delayed, from people abandoned in airports to seek emergency accommodation and alternative flights home, to those still chasing compensation months later.
"Airlines' unacceptable treatment of passengers cannot be allowed to stand."
CAA head of consumers Anna Bowles told the PA News Agency: "Bounceback in passenger numbers was at times overshadowed by the challenges that the aviation sector faced in the early summer of 2022, which saw an unacceptable level of flight cancellations and delays."
Which? has said that it wants the Government to make it easier for passengers to claim their money back when airlines "fail in their responsibility".
Rocio continued: "We are calling on the Transport Secretary to act without delay and give the Civil Aviation Authority the powers it needs to fine airlines when they break the law and fail in their responsibility to passengers.
“The government should also drop its proposals to drastically cut the compensation passengers are owed by airlines when domestic flights are delayed or cancelled, which would effectively act as a reward for their failures last year and potentially lead to even worse standards of service to passengers.
"It should also introduce a mandatory dispute resolution system, so travellers are no longer forced to pursue claims through the small claims court at their own expense."
A Department for Transport spokesperson said: “It’s vital passengers feel confident when flying and if flights are disrupted, airlines are responsible for issuing refunds and compensation where necessary.
Don't miss the latest news from around Scotland and beyond - sign up to our daily newsletter here.
