The report, which was published yesterday, centered on an undercover investigation by the newspaper into how a number of car hire firms reportedly put extra charges on to holidaymakers’ bookings.

Brands such as Europcar, Goldcar and Firefly were all named as having added charges to bookings made by a reporter in Spain.

Following the report, Flexible Autos said it wanted to reassure agents making bookings on behalf of their customers.

Sue Dixon, managing director at Flexible Autos, said: “While we have not been directly affected by this report, we do sympathise with agents who sit at the ‘sharp end’ of such investigations and who will no doubt face some difficult questions from customers about car rental charges during the peak summer months.

“First and foremost, we continue to work hard with our suppliers in order to address transparency issues. It can be really confusing booking car rental online, hence we firmly believe in the huge benefits that come with booking via a travel agent in advance, as they will be able to advise and take the time to find the best product for the customer.”