The cross-Channel train operator began a campaign in July last year aimed at boosting sales in August and September. It said fares were available “from just £39 each way” to Paris, Brussels and Lille, but a consumer who found only one ticket from London to Paris at this rate alerted the ASA.

Eurostar told the ASA 39,000 seats had been available at this fare to the three destinations, arguing this was “a significant number”.

Eurostar argued this number was clearly displayed and that therefore availability was not exaggerated.

The train operator also said the ad had been sent to consumers only once, which it argued reduced the risk of exaggerating how many promotion fares were available. It added the supply of promotional fares would naturally diminish as they were sold and had received no complaints itself.

The ASA disagreed, saying Eurostar’s campaign meant consumers would assume the August and September dates of the promotion meant fares would be available to book throughout those months.

“We also considered that consumers would expect to find the tickets available at the “from” price across a range of dates and times within that period, and that they would have a reasonable chance of obtaining a seat at the advertised price,” the ASA said.

It added: “The terms and conditions of the promotion stated that, as of 12 July 2023, there had been 9,500 standard class seats available on both the outward and return journey (to Paris) at the stated “from” price, for travel between 16 August 2023 and 13 December 2023. 

“Data provided by Eurostar in their response showed that the £39 fares had made up a very small percentage of available tickets for travel between London and Paris, and Paris and London. 

“We therefore considered that Eurostar had not demonstrated that a significant proportion of tickets between London to Paris and Paris to London had been available “from” £39 during the promotional period.”

The ASA ruled Eurostar must ensure that when using “from” price claims that a “significant proportion” of the advertised fares are available.

Eurostar said: "We value customer feedback, including complaints and take great care in the way that we word our advertising and the number of tickets that we offer at the promotional price during particular time periods.

"We understand and take on board the ASA’s ruling which is related to seat availability in part of the promotional period, and we are committed to ensuring that this scenario does not occur again."