Twelve countries including Italy, Germany and Bulgaria are on course to join the quarantine-free green list this week and open up travel to unvaccinated holidaymakers, according to an analysis of official data.

The 12 countries meet the green list criteria used by government scientists to determine if countries’ infection rates, the testing capability, vaccination levels and risk from variants are low enough to justify inclusion.

The 12 also include Canada, Austria, Latvia, Lithuania, Poland, Slovakia, Switzerland, Hong Kong and Taiwan and would bring the total of countries on the green list to 39, according to the analysis by Robert Boyle, a former BA strategist whose predictions have been accurate previously.

The Balearic islands of Ibiza, Menorca and Mallorca, Portugal’s Madeira, Malta, Gibraltar and Israel are the only other viable holiday destinations on the green or green watch list, which has been expanded only once since it was launched last month.

The green list is reviewed every three weeks and is due for its latest update this Thursday in advance of travel being allowed the following week.

It follows last week’s change in the rules that will allow fully vaccinated British holidaymakers to travel to more than 140 amber countries without having to quarantine on their return. 

Travel countries on the red, green and amber list

Unlike amber countries, unvaccinated Britons can travel to green countries without having to quarantine on their return, making them attractive to the majority of under-30s who have yet to be fully jabbed. All adults visiting both green and amber countries have to take a PCR test on their return.

Mr Boyle’s analysis is based on reverse engineering the green list to work out the algorithm that the Government’s joint biosecurity centre uses. 

As well as a low variant risk, a green country has an infection rate at or below 20 per 100,000 of the population, test positivity at 1.5 per cent or less and a testing rate of one or more per 100,000.

The study’s top prediction for going green this week is Canada with a case rate of only 9.6 per 100,000 and declining, test positivity at one per cent, and 111 vaccine doses administered per 100 people, almost matching the UK’s 118 and catching up fast.

Malta faces demotion from the green to the green watch list because of its rising infections but there are 11 red list countries that the analysis suggests should turn amber: Bahrain, Ethiopia, India, Kenya, Pakistan, Peru, Philippines, Qatar, Sri Lanka, Turkey and the UAE.

However, Mr Boyle cautioned that the Government could hold back on giving the go ahead to any more green countries because of the July 19 loosening of restrictions on amber countries.

“It is quite possible that politicians will seek to minimise the changes to the lists themselves. With the delta variant driving an upsurge in cases across the world, they may be particularly cautious about moves from amber to green which may need to be subsequently reversed,” he said.