Just eight countries - including Ireland, the United States, Israel and Australia - could be included on the government's travel "green list", meaning Brits will not have to quarantine unless they test for Covid, it is claimed.
Modelling by the travel industry suggests that Gibraltar, Iceland, Malta and New Zealand could also be deemed safe for travel when non-essential foreign trips are allowed again from next month.
However Australia and New Zealand are currently closed for foreign arrivals to protect their populations from the virus, which has killed more than three million people worldwide.
Everywhere else would either be "amber" or "red" - meaning people have to quarantine when they arrive in the UK.
The countries have been identified by analysts based on the government's "risk" criteria for travel.
Under Boris Johnson's "roadmap" out of lockdown, non-essential foreign travel, which is currently banned, could be allowed again from May 17 if Covid cases in the UK continue to fall.
A report by Robert Boyle, former strategy chief at BA, and circulated in the travel industry, said that most of Europe will be classified as "amber" or "red" - meaning quarantine will be required, according to The Telegraph.
It ranks 52 countries based on vaccination rates, infection levels, variants and capacity for genome sequencing - the four criteria used by the UK government.
People arriving from countries listed as "red" would be required to quarantine at a hotel at a cost of £1,750 - making them far less appealing as holiday destinations.
France, the Netherlands, Turkey, Croatia, Sweden, Belgium and Luxembourg should be "red" under the criteria, researchers found, but this is unlikely to happen for political reasons, the report said.
Countries classified as "amber" will require people to quarantine at home for 10 days after arrival.
High Covid rates in Spain, Greece, Italy and Cyprus mean they are likely to be "amber" - but it is possible islands will be given their own rating.
The report said: “Last year, the Spanish and Greek islands were given a lower-risk rating than the mainland, and that could happen again this year."
Just five countries have vaccinated more than five per cent of their population - the US, Israel, Gibraltar, the UAE and Malta - while only seven have less than 50 cases per million people.
These are China, Hong Kong, Australia, New Zealand, Israel, Iceland and Gibraltar.
Variant rates are worst in Turkey, Luxembourg, Finland, Belgium, France, Holland and South Africa, The Telegraph reports.
