To enter the UK you’ll need:
Passport
Vaccine Cert
LFT or PCR completed within 48 hours of travel.
Passenger Location Form completed no more than 48 hours before travel.
A pre-booked PCR test to be taken 2 days after you arrive in the UK, when you book that, you’ll be given a code, you’ll need this code to complete the PLF above. I don’t know how tourists are managing this.
To return to France
Passport
Vaccine Cert
LFT or PCR taken no more than 48 hours (LFT) or 72 hours (PCR) before travel.
A declaration form (from the French erm… website) signed.
LFT tests in France are €29. A Day 2 PCR test should cost less than £50 if you shop around, an LFT for return to France about £40 if you shop around.
I went to France about 2 weeks ago, getting into France is pretty easy, a nice (ours was anyway) French Guard will check the various bits of paper and wish you a nice trip.
Entering chippy little England was a massive PITA, first Border Force will talk to you like something they stood in, whilst doing their best Ant Middleton impression and check everything, then, at least for us 3m after we passed the gate another Border Force knob in a car stopped us to check the car, again, then drive a few meters more when the Guy from the Ferry co will check everything again. Takes 45 mins to go about 30 meters.
That said there were only 6 cars on the Ferry that day, they might have been bored, but the 19th there’s no way they’ll be able to check all that, not a chance, there are 6 gates in Calais, it took us 40 mins to clear the only one open and a cross-channel Ferry can take up to 1000 cars. A quick bit of maths tells me if 1000 cars arrive in Calais on the 19th of July and they’ve got all 6 gates open, if they check everyone to the same degree they checked us, it’ll take 4 and a half days to clear everyone.