FRANCE TRAVEL CERTIFICATE NOW REQUIRED
Anyone making a journey to an airport, port or train station in order to return to the UK will need to download and complete an “attestation” or declaration certifying their reason for travel. This is available on the French Ministry of Interior website. Please note that you are permitted to hand write and sign a similar declaration if you are unable to access printing facilities. You can carry a physical copy of the declaration or an electronic version. This e-attestation is available on the Ministry of Interior webpage.
On 6 April 2020, the French authorities introduced a separate requirement to provide a certificate or “attestation” to enter mainland France.
Further information can be found here https://uk.ambafrance.org/Coronavirus-Covid-19-transports-vers-la-FranceBack