Passengers are entitled to compensation if their flights are delayed by three hours or more, but a legal challenge by airlines has seen claims put on hold

Yves Bot, an ECJ advocate general, has opposed a joint legal challenge by British Airways, easyJet, Tui Travel and the International Air Transport Association to compensation rules introduced in November 2009.

Although his statement does not amount to a legal ruling, the ECJ is expected to make a binding decision on the challenge in the coming months.

Under current regulations passengers flying to or from an EU, Swiss, Norwegian or Icelandic airport, or with an EU, Swiss, Norwegian or Icelandic-based airline, are entitled to meals and refreshments and free telephone calls or emails if their flight is delayed by three hours or more.

They are also entitled to compensation of between £200 and £480, depending on the distance of the flights. However, airlines do not have to pay compensation if they can prove the delay is not their fault, and has been caused by “extraordinary circumstances”.

A spokesman for BA said: “We are aware of today's non-binding opinion given by the advocate general and we await the final ruling in due course.

“The European Court of Justice ruling from November 2009 has come under criticism from many parties and we also believe the ruling was wrong.”

Nick Trend, Telegraph Travel's consumer correspondent, suggested that even if the ruling is upheld, a sudden change in what passengers are entitled to claim is unlikely.