Switzerland has effectively banned British tourists after it added the UK to its quarantine list.
It means that Britons entering the country must produce a negative Covid test and quarantine for 10 days if they travel Switzerland.
It will dash hopes for thousands of winter holiday-makers who were planning on hitting the slopes this Christmas.
Swiss authorities have widened quarantine restrictions to travellers from Britain, Czech Republic, the Netherlands, Egypt and Malawi, in a bid to contain the Omicron coronavirus variant.
Two cases of the new variant were confirmed in Nottingham and Essex on Saturday.
Experts fear that Omicron could be more contagious than other variants and more resistant to vaccines.
Thirteen cases of Omicron were detected among travellers from South Africa who flew into Amsterdam on Friday.
Britain has added ten countries to its red list in response to the new variant.
Many other countries have imposed travel restrictions on countries in southern Africa.
Israel has announced plans to ban all foreigners from entering the country.
If the travel restrictions are approved, Israel will become the first nation in the world to completely shut its borders in response to the Omicron variant.
Prime Minister Naftali Bennett announced that the ban is set to last for 14 days.
Interior Minister Ayelet Shaked said: “Our working hypotheses is that the variant is nearly in every country…and that the vaccine is effective, although we don’t yet know to what degree.”
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