Thousands of mid-term holidays could be threatened as Covid-19 cases rise in Greece and Italy.
There are also new guidelines in the Czech Republic, where the capital Prague is a popular meeting place for British party groups, Slovakia and ski resorts in Austria.
Sweden and Poland are also at risk of the UK government imposing new quarantine restrictions.
Mainland Greece is nearing the UK quarantine limit of 20 cases per 1,000 residents, while Italy’s rate doubled to 19.6 from 10.8 per 100,000 residents last month.
However, a travel corridor could be established between the UK and the island of Sicily, where the infection rate is 16.
If destinations in Greece and Italy were to be removed from the UK’s safe travel list, it would destroy mid-term vacation plans for thousands of families in the UK and cause havoc in the aviation and airport industries already plagued by the coronavirus pandemic.
Poland and Sweden could also be removed from the British quarantine-free travel list due to rising infection rates. Poland reports a value of 22.7, Sweden 26.3 per 100,000 inhabitants.
Meanwhile, the Czech Republic plans to announce a state of emergency with stricter restrictions on public gatherings from Monday as the number of positive coronavirus tests increases.
Neighboring Slovakia also wants to raise the curbs, as sports and cultural events as well as church services are banned from tomorrow.
Masks are mandatory outdoors when people are closer than two meters apart, and a 10pm curfew will be put in place for hospitality.
In Austria, bars and restaurants in winter sports regions will only offer table service inside and outside.
Grouds must be one meter away from each other and singing and dancing are not permitted, with music only playing in the background.
Social gatherings are limited to 10 people, excluding children. The opening times are limited. The venues close at 1 a.m.