Abta said the OTA had left “following ongoing discussions” around refunding customers when the FCO advises against all, or all but essential travel to a destination.

“We recognise that the widespread imposition of advisories against travel places many Abta members under enormous pressure regarding refunds,” an Abta spokesperson said.

“But Abta has consistently maintained that the underlying obligation to refund remains, as has been the longstanding practice of the travel industry, and this has not changed as a result of Covid-19.

“Abta believes this is important to ensure consumer confidence in the package holiday market.”

A spokesperson for On the Beach said: "The travel industry is facing unprecedented challenges, and changes are inevitable as businesses and trade organisations adapt. 

"On the Beach has been an Abta member since 2004, however the current circumstances have presented difficult decisions, and different legal interpretations on complex matters. 

"As of late last week, On the Beach and Sunshine.co.uk have informed Abta that they will resign their memberships.

"On the Beach and Sunshine.co.uk package holidays continue to be financially protected by the Atol scheme and our ring-fenced trust account."