On the CAA website it states:
After the UK ‘recognition’ period ends on 31 December 2022
From 1 January 2023 all EU licences and EU medical certificates will no longer be recognised for UK licences. Licence holders will need a UK PART FCL Licence and UK PART MED Medical Certificate to fly G-registered aircraft, and separately an EU PART FCL Licence and EU PART MED Medical Certificate for EU licence privileges (similar applies to ATCO licence holders with Class 3 medical certificates).