The new category was added to the travel traffic light system on Friday, with only France classified as ‘amber plus’. People travelling to the UK from France now need to quarantine for 10 days, even if they have been double vaccinated. The government made the move following concerns about the rise in Beta infections (the South African variant) in France.

Up until 19 July, all arrivals in the UK from amber list countries had to quarantine at home for 10 days. But since last Monday, double-jabbed Brits don’t have to isolate when they arrive in the UK from an amber country.

However, arrivals from an amber plus country must self-isolate for 10 days and take two tests, regardless of whether they’ve been fully vaccinated or not.

Reports that Spain and Greece could be moved to the new list are worrying for both holidaymakers and the travel industry. However, the government has refused to confirm the move.

Analysis by Labour shows that nearly six million Brits’ summer holiday plans could be ruined if the two countries are classified as amber plus. Figures show that an estimated 5,857,558 people have booked holidays to France, Spain or Greece during Quarter 3 of 2021.

These travellers could find themselves slapped with last minute quarantine requirements and the associated costs. Arrivals in England can get Covid tests from £25 each – adding up to £200 for a family of four – but people flying into Wales or Scotland have to pay £170 for two NHS tests if they have been to an amber list country. This adds up to £680 for a family of four.

The creation of a new traffic light category drew criticism from French officials, who were reportedly not told about the new measures until they appeared in the press, and from senior figures in the travel industry.

Jim McMahon, Labour’s shadow transport secretary, said: “Boris Johnson is presiding over a summer of chaos. He and his cabinet appear to be in meltdown with their mixed messages and making up policy on the hoof, with one million children out of school at the end of term and international travel rules causing widespread confusion.

“Not only have they failed to protect our borders, allowing Covid cases to rocket – they also refuse to be straight with the public and give them the information they need to book travel with confidence, with clear information on the direction of travel of infections in each country.

“Families who have booked holidays in good faith now risk losing out – 10-day quarantine is simply not an option for many people who are already struggling financially thanks to the pandemic.”