The two Mercury ads offering holiday deals were published in the national press during June 2018 and featured lead-in “from” prices and “free” weeks as part of the campaign.

But two members of the public complained to the ASA because they “were unable to find holidays at the advertised from prices” and challenged whether the ads were “misleading and could be substantiated”.

Mercury Holidays, through its parent company Sunspot Tours, responded to the complaint by saying that “flights were based on low-cost airlines which changed daily” and there were 30 flights available at the lead-in price.

But the ASA upheld the complaint against Mercury and said: “We acknowledged that 30 seats out of a total of 80 were available at the lead-in price and those 30 seats were split across five dates in May.

“However, we considered that seats at the lead-in price should have been spread evenly across the advertised travel period of May 2019.”

ASA ruled that the two Mercury Holidays adverts “must not appear again in their current form”.

“We told Sunspot Tours not to use “from” prices if they were unable to demonstrate that the price in question was available to consumers at the time the ad appeared, in reasonable quantities and spread evenly across the advertised travel period,” said the ASA in its ruling.

“We also told them to ensure that, where holiday prices were subject to change and had limited availability that was made clear in a prominent statement.”