"If we find that businesses are breaching consumer protection law, we will not hesitate to take further action."
Evening Standard has contacted lastminute.com for comment.
It comes as Ryanair, which had drastically cut flight schedules over the Christmas period as lockdowns hit across Europe last month, announced it was adding another 24 flights from locations including London Stansted and Gatwick Airport back in from December 16 "as a result of increased demand across the network" as families attempt to reunite over Christmas.