Ministers are considering adding France to the travel red list, with officials ordered to conduct a "deep dive" into data concerning the spread of the Beta variant discovered in South Africa, a report says.
Senior Whitehall sources told The Telegraph that the proposal was discussed at a meeting on Wednesday as part of the review of international travel.
At the meeting, the Balearic Islands were demoted to the amber list only a fortnight after turning green.
Insiders said the recommendation to move France from amber to red, requiring all arrivals to undergo hotel quarantine for 10 days, was based on an analysis by the Joint Biosecurity Centre.
Officials are said to be alarmed about the prevalence of the Beta strain in France, which is said to be significantly higher than global levels.
But others said there were "mixed opinions" about how to deal with the situation. Ministers agreed to monitor it closely.
The JBC and the Department of Health have been asked to scrutinise data coming out of France.
Meetings are expected to take place in the coming days, with sources indicating on Thursday night that the situation could be discussed at a meeting of the Covid-19 Cabinet sub-committee as early as Monday.
It is thought that UK Prime Minister Boris Johnson will be reluctant to put France on the red list, having warned of a disruptive effect on trade and supply when similar calls were made in March.
Government sources said they did not expect any decision to be made "imminently" as the data needed to be analysed in more detail.
The number of recorded Beta cases in France remains well below the peak seen in May, with the country's overall case rates remaining low at 46.5 for every 100,000.
Almost 50 per cent of French adults have been fully vaccinated.
But sources say ministers and officials are alarmed at the prospect of the variant being spread in the UK this summer. It is believed to be more resistant to vaccines than other strains.
"They are worried about the South African variant because they think it escapes the vaccine, although they don't have evidence of that yet," one source said.
"It appears to be why a lot of countries in Africa and the Middle East are on the red list despite low prevalence rates."
Others in the government believe that as the Delta variant continues to take hold across Europe, its greater transmissibility will mean other strains become more scarce, reducing the need to put France on the red list.
But if the Beta variant continues to spread, it has been suggested the government could issue guidance to holidaymakers asking them to consider the risks of travelling to France.