Hundreds of tourists will be heading home to Britain tonight still don’t know whether they will have to quarantine themselves when they arrive back at Harwich after the government added Holland to the list of countries from which travellers would have to self-isolate.

The overnight Stena Line ferry leaves the Hook of Holland for Harwich at 10pm and arrives at the Essex port at 6.30am. The new rules say that anyone who arrives in the UK after 4am has to quarantine themselves for 14 days after the number of cases in The Netherlands rose over the last few weeks.

But the ship actually passes into UK territorial waters at 3am – an hour before the deadline. A spokesman for Stena Line said they were seeking clarification from the Department for Transport on when the government considered to ship to arrive in the UK. A government spokesman said officials were still to decide whether travellers on the ship would have to go into quarantine.

The Stena spokesman said all spaces on the day sailing from the Hook to Harwich, on which passengers would definitely not have to go into quarantine, were booked.

He said: “This news is very disappointing. We had been building up numbers over recent weeks after what has been the most difficult year we have ever had. We hope these restrictions do not last for long.”

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There are a number of exemptions from the quarantine rules – including for international truck drivers – so he did not expect the new restrictions to have a serious effect on commercial traffic.

Holland had the restrictions brought in along with France, Malta, Monaco, Aruba and the Turks & Caicos Islands.

They join a list of countries already on the list including Spain, Portugal, Belgium and Luxembourg.

And today it emerged that British tourists in France are being charged hundreds of pounds to return home before quarantine restrictions are imposed.

Air fares are more than six times higher than normal for flights from Paris to London on Friday, with the cheapest British Airways tickets being sold for £452.

The lowest priced Eurostar tickets available on Friday morning are £210.

Travellers willing to pay these inflated fares could still miss out due to many services already being fully booked.

Transport Secretary Grant Shapps insisted the Government had taken “a practical approach” to the new restrictions. Mr Shapps said an estimated 160,000 holidaymakers are expected to try to return to the UK from France on Friday. There “had to be a cut-off”, he told BBC Breakfast.

The latest 14-day cumulative figures from the European Centre for Disease Prevention and Control show 32.1 coronavirus cases per 100,000 people in France, compared with 18.5 in the UK.

The decision to add the Netherlands was made after a 52% increase in newly reported cases between August 7 and 13 after a consistent series of rises in previous weeks.

Over the past week, there has been a 273% increase in newly reported cases in Turks & Caicos, a 1,106% increase in Aruba and a 105% rise in Malta.