Extra ferry services have been added, but Eurotunnel trains are booked up and air travellers face steep prices.
France warned it would take "reciprocal measures".
The Netherlands will warn against all but essential travel to the UK once the restrictions come into force on Saturday, but it said it will not introduce reciprocal measures.
The countries were targeted for quarantine restrictions because their infections rates exceeded 20 per cases 100,000 people over seven days, Transport Secretary Grant Shapps said.
"We've worked so hard in this country to get our level of infections down, the last thing we want do is to have people returning and bringing the infection with them. It's to protect everybody," Mr Shapps told BBC Breakfast.
He said there are about 160,000 British holidaymakers currently in France.
The deadline left many of them in a frantic rush for plane, train or ferry tickets costing hundreds of pounds.
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Tom Duffell, who runs a small business, cut short his holiday to Nice - with his wife and two children - by four days and booked a last minute flight home.
"We were enjoying a nice cocktail last night and suddenly a news flash pops in and a scramble to book flights," he said.
"We've had to spend about £800 because we can't afford to take another two weeks off work."
- hhhh Aug. 15, 2020