The right of UK air passengers to force airlines to pay compensation for long flight delays has been suspended by the High Court.
A European Court of Justice (ECJ) ruling last November gave passengers the right to compensation for long delays, not just cancellations.
But the High Court has, at the request of UK airlines, referred the matter back to the ECJ for a further hearing.
It means UK courts will not hear any more cases until the ECJ rules again.
The Civil Aviation Authority (CAA), which enforces the airline regulations, said it would defend the current position at the next ECJ hearings.
"The High Court stayed our enforcement powers so the courts won't hear cases in the interim," a spokesman said.
"But our view of the law hasn't changed - we wish to enforce the position laid down by the 2009 ruling."
Until last November, European rules awarded airline passengers cash compensation if their flights were cancelled, but not if they were delayed.
If passengers were delayed the airlines had only to offer meals, refreshments, two free telephone calls and, for an overnight delay, hotel accommodation and transfers to and from the hotel.
That changed when the ECJ effectively re-wrote the original 2004 regulations, and said that people whose flights were delayed should be treated as if their flights had been cancelled.
That meant cash compensation should be awarded, in addition to their other rights, if delays lasted longer than three hours.
However, the UK airline industry opposed the move. BA, Easyjet, the tour operator TUI and the International Air Transport Association (IATA) took the matter to the High Court, to persuade it to ask the European court to look at the issue again.
"It was an unexpected judgement last November," said aviation lawyer Sue Barham at law firm Barlow, Lyde and Gilbert.
"The rules don't say there is an obligation to pay compensation for delayed flights but the ECJ decided that that is what they meant."
Sarah McIntyre at Easyjet said: "It is important to clarify that this case will not affect delayed passengers' right to care such as phone calls, hotel accommodation and food, and we will continue to fully comply with EU regulations for claims relating to cancellations or denied boarding."
Since November some airlines have been paying up when delayed passengers have demanded compensation, while others have tried to stall and avoid paying, arguing that the ECJ judgement was wrong.
A stay on any new compensation cases in the UK courts, and refusal by UK airlines to pay compensation to passengers who merely ask for it, could last for two years.
"There will be a further hearing and I do not expect another judgement until the first half of 2012," said a source close to the airlines.
Despite the new round of court hearings, a CAA spokesman explained that a UK passenger could still make a claim for delay compensation in another EU country if an EU airline was involved.
The referral back to the ECJ is not a formal appeal - such a procedure does not exist - but it is being asked to reconsider the issue and change its mind.
Separately, some airlines have been fighting their obligation to pay food and hotel costs, for instance following the widespread disruption caused by the volcanic ash cloud over much of Europe during the spring.
Last week, the European Commission threatened to take legal action against the Dutch airline KLM which has been reimbursing its passengers for the cost of just one day and one night's delay.
Ryanair initially threatened not to reimburse passengers whose flights were cancelled due to the ash cloud, but it backed down under pressure from the UK and Irish authorities.