UK drivers using medical cannabis should know that the ‘in charge’ rules apply...

https://evpowered.co.uk/feature/electric-vehicles-and-medical-cannabis-what-uk-drivers-need-to-know-about-the-law/

UK drivers using medical cannabis should know that the ‘in charge’ rules apply even when parked and charging an electric vehicle. The legal THC limit is 2 micrograms per litre of blood