TUI has cancelled all British holidays to mainland Spanish until August 9th in response to government decision to reintroduce quarantine procedures.
However, the firm said all those going to the Balearic and Canary Islands could still travel as planned from Monday – as both are excluded from the new rules.
The airline industry has reacted with dismay to the decision, which was unexpectedly announced over the weekend.
The Foreign & Commonwealth Office (FCO) is advising against all but essential travel to mainland Spain.
Quarantine measures apply to those returning from mainland Spain, the Canary Islands and the Balearic Islands, such as Majorca and Ibiza.