Travel Network Group chief Gary Lewis said the decision to move the Balearic Islands from the green watchlist to the amber list highlighted the reality for the travel industry that summer would be "on a much smaller scale" compared with pre-Covid years, despite concessions that – technically – allow travel to a wide range of potential destinations.

"Many holidaymakers have opted for UK breaks for summer 2021 because of a lack of confidence in the government’s erratic approach to travel earlier in the year," said Lewis.

"Even though fully vaccinated customers will be able to travel to amber list countries without quarantine from Monday [19 July], this announcement leads to unease about how quickly countries can change from list to list.

"Despite reports of increases in overseas enquiries, many travel businesses won’t earn any revenue from future bookings until the customer has taken their trip because the industry is commission-based.

"Therefore the travel industry needs ongoing financial support, and an extension of measures such as furlough, to bridge the gap between now and a time where bookings are being redeemed and travel is getting back to pre-Covid levels."

WTTC senior vice-president Virginia Messina said the decision to revoke the Balearics’ green status would throw tens of thousands of summer holidays into disarray".

"Businesses given the lifeline of holidays to the Balearics will also be left floundering as bookings collapse and customers clamour for refunds, piling on further financial pressure," said Messina.

“There may be some good news with Croatia and Bulgaria moving up the scale and being added to the green list. But the overall impact is one of confusion, which will only deter more Brits from holidaying abroad as the summer season slips away."

Abta branded the decision to move the Balearics to the amber list as a "step back for the travel industry" at a time when thousands of travel jobs and businesses were in "desperate need" of a successful summer season.

"This further emphasises the urgent need for tailored financial support for a sector that has struggled to make any meaningful revenue for almost 18 months now," said a spokesperson for the association.

“Helpfully, from Monday 19 July, fully-vaccinated travellers returning to England, Scotland and Wales from amber list countries will no longer need to self-isolate or take an additional test on day eight, so this will minimise the disruption for vaccinated holidaymakers, but quarantine for non-vaccinated travellers remains a significant obstacle."

Abta said consumer confidence would be an essential pillar of the industry’s efforts to trade its way out of crisis. "Government must be more transparent about the criteria being used to move countries between the green, amber and red lists to allow travel businesses and customers alike to plan ahead," said the association.

"The government also needs to continue to capitalise on the successful vaccine roll-out by expanding the green list in line with scientific evidence and reducing the need for and cost of testing, which is a significant barrier to travel for many people.

"Sufficient border control resource must also be provided at our ports and airports to help make travel as smooth as possible."