Thanks for your quick response. I put the car back on charge at home and when it had reached 100% i tried it again and the selector was able to select drive and reverse ok. Before I plugged the car in, I completely powered it down for the duration of the charge - about an hour and a half.
It looks like the 12 volt battery had run down. I did some more research whilst the car was charging and found that other owners had experienced similar problems. I’ve only had the car from new since September, so I was quite worried about the situation.
Thanks again for your help.
This forum is absolutely brilliant, putting users together to share problems and solutions. With EVs it seems that this is a better way to find solutions than going to a dealer!