A new investigation reveals that 37 million passenger journeys to or from the UK were delayed by 15 minutes or more between June 2014 and May 2015.

 The investigation carried out by the consumer group Which? also says delayed airliner passengers are potentially missing out on millions of pounds of compensation.

Which? found that about 900,000 delayed passengers could be eligible for compensation but only over one-third of them have ever claimed.

The group went on adding that more than 9,000 flights are delayed for three hours or more each year. It urged the delayed passengers to assert their rights and hold their airline accountable for those delays.

According to the state-run BBC, passengers delayed for over three hours are entitled to up to 600 euros and those protected by the Denied Boarding Regulation have to be flying with an EU-based airline or flying from an EU airport.

The investigation drew on a survey of about 7000 people who had experienced delays in the UK airports. Half of those surveyed said they didn’t receive any information in advance about the delays.