Chancellor Rishi Sunak has warned holidaymakers of the risk of travelling abroad during the coronavirus crisis amid concerns France may be the next nation to be added to the quarantine list.

He said on Friday that ministers will “not hesitate” in ordering travellers coming back from countries with high Covid-19 rates to isolate for 14 days, as Belgium, Andorra and The Bahamas lose their exempted status.

Travellers returning to the UK from those three nations from Saturday must enter quarantine, and there are fears those coming back from France could be next with cases there increasing.

Eurostar said it recorded an increase in passengers travelling on its trains from Brussels to London on Friday, beating the deadline.

Mr Sunak told Sky News: “It’s a tricky situation. What I can say to people is we’re in the midst of a global pandemic and that means there is always the risk of disruption to travel plans and people need to bear that in mind.

“It’s the right thing for us to do to keep everything under review on a constant basis talking with our scientists, our medical advisers, and if we need to take action as you’ve seen overnight we will of course not hesitate to do that and we’re doing that to protect people’s health.”

France’s coronavirus rate has increased steadily in the past month to 13.2 new infections per 100,000 people, suggesting the spread is worse than in the UK, which has a rate of 8.4.

However, France still appears to be faring better than Belgium, which has seen its rate soar to 27.8. It also has a rate lower than Spain’s when it was added to the restriction list at around 27.4.

Earlier Transport Secretary Grant Shapps said rising Covid-19 infection levels in Belgium, Andorra and The Bahamas meant they would be added to the quarantine list.

The measure will come into force in England, Scotland and Northern Ireland from 4am on Saturday after they were introduced in Wales from Friday.

The Foreign and Commonwealth Office also updated its travel advice to warn against all but essential trips to the three countries.

The Department for Transport clarified that people driving to the UK from Germany or the Netherlands via Belgium will need to self-isolate for 14 days unless, while in Belgium, all passengers remain in their car and no-one joins them.

Anyone who travels on a train which passengers get on or off in Belgium will also need to quarantine.

This means Eurostar passengers travelling from Amsterdam to London will need to self-isolate, as the journey involves changing trains in Brussels.

Eurotunnel Le Shuttle, which operates vehicle-carrying trains through the Channel Tunnel between Kent and northern France, said its phone lines and live chat service were “extremely busy” on Friday.

It brought in extra staff to deal with the demand and advised customers that most bookings can be amended online.

Brunei and Malaysia have been added to the Government’s travel corridor list, following a decrease in confirmed cases of coronavirus, meaning arrivals from these countries no longer need to quarantine.

In Andorra, new cases per week have increased five-fold since mid-July, while in The Bahamas the weekly case rate peaked at 78.6 last week, up from 3.1 in the middle of last month.

The UK’s move to add Spain onto the quarantine list on July 26 sparked a diplomatic row with the nation and caught out holidaymakers who had already flown over, including Mr Shapps.

It also angered transport bosses who have called for increased testing to reduce the isolation period.