Camera is not for reversing it’s just to see who is behind me when driving
Is it legal to view a screen depicting moving images whilst driving ?
Yes,
https://www.legislation.gov.uk/uksi/1986/1078/regulation/109/made
See 109, 1, section (c).
I stand corrected, good news for the OP.
Hmm. I see regulation 2 says "2) In this regulation “television receiving apparatus” means any cathode ray tube carried on a vehicle and on which there can be displayed an image derived from a television broadcast, a recording or a camera or computer".Yes,
https://www.legislation.gov.uk/uksi/1986/1078/regulation/109/made
See 109, 1, section (c).
A lot of new HGVs(and coaches) I've seen lately don't have door mirrors, they have rear pointing cameras and an LCD screen inside the cab on either side for the driver to see.