UK EV drivers using medical cannabis should be aware of the ‘in charge’ rules,...

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

UK EV drivers using medical cannabis should be aware of the ‘in charge’ rules, which mean you can be tested even while parked and charging. The legal THC limit is 2 micrograms per litre of breath