Websites selling airline tickets are misleading and ‘ripping off’ passengers, a study by the European Commission has suggested.

In the sweep of 100 websites in 13 European countries, one in three were found to be breaching consumer law. The main problem was airlines not providing the total price in their advertising.

“For the consumers, the final price to pay when actually booking the ticket is generally higher due to a series of added charges that vary from so called airport charges to handling fees, booking fees or charges related to credit card payments, priority booking, luggage and fuel,” said the report.

There was also a lack of information on availability of advertised offers and misleading use of pre-checked boxes, such as for insurance or priority boarding.

Ryanair was named one of the offenders as well as Austrian Airlines.

European Union consumer commissioner Meglena Kuneva said: “This report shows that there are serious and persistent problems with ticket sales through the airline industry.

“We will need to see credible evidence of improvement to clean up these sales and marketing practices within the airline sector by May 1 next year or we will be left with no choice by to intervene.”

The Office of Fair Trading took action against 13 British airlines that did not include hidden costs in August last year.