The government made the announcement late last night - the rules will take effect from 4am tomorrow following increases in coronavirus cases in all three countries.
Boris Johnson has warned that Westminster will be "absolutely ruthless" when it comes to the safe-travel list.
This mean travelers trying to return from France on Friday to avoid the quarantine restrictions face paying hundreds of pounds.
British Airways is charging £452 (€500) for the cheapest tickets to fly direct from Paris to London Heathrow.
The same journey on Saturday can be made with the airline for just £66 (€73).
The cheapest ticket on a Eurostar train from Paris to London is £210 (€232), compared with £165 (€182) on Saturday.
Following the UK government's annoucement, we would like to advise customers currently in France, and hoping to return early, that they must amend their tickets online at https://t.co/CcFUUhpuod, before travelling to the French terminal. -14/08/2020 - 07:50 CET ^Audrey#VitalLink pic.twitter.com/UxSGy3Uqoh
— Eurotunnel Le Shuttle (@LeShuttle) August 14, 2020
The cost of taking a car through the Channel Tunnel on Eurotunnel Le Shuttle services on Friday is £260 (€280)
This is £60 (€66) more expensive than journeys taken on Saturday.
P&O Ferries has limited availability, but one person travelling with a car from Calais to Dover can buy a ticket for £200.
Travellers in the south of France face a struggle getting back to the UK before the 4am Saturday quarantine deadline.
Many direct flights to the UK on Friday are sold out.
The FCO now advise against all but essential travel to #France based on the current assessment of COVID-19 risks. If you're returning to the UK from France, you may need to self-isolate on your return. More info: https://t.co/JqWcOTBj4J pic.twitter.com/wdsduFpqMu
— FCDO Travel Advice (@FCDOtravelGovUK) August 13, 2020
Flight booking website Skyscanner suggested there were no direct flights from Biarritz to London.
The cheapest option it offered was to take one flight to Paris, another to Belfast and a third arriving at London Stansted shortly before midnight, at a total cost of £284 (€314)
The lowest priced ticket involving just two flights is £579 (€640) with Air France, changing in Paris.
Whichever mode of transport travellers use, they will need to move quickly as many services will be fully booked by Friday afternoon.
