There are strict legalities for viewing CCTV. It's covered, you can request it :
www.gov.uk/request-cctv-footage-of-yourself
You have the right to request closed circuit television (CCTV) footage of yourself.
The CCTV owner must provide this within 40 days, and can charge up to £10.
You need to make a request in writing to the owner of the CCTV system. The owner’s details are usually written on a sign attached to the camera, unless the owner is obvious (like a shop).
You should tell them you’re requesting information held about you under the Data Protection Act, and provide information to help them identify you, like:
a specific date and time
proof of your identity
a description of yourself
The CCTV owner must provide you with a copy of the footage that you can be seen in. They can edit the footage to protect the identities of other people.
The CCTV owner can invite you to a viewing of the footage if:
they’re unable to provide you with the footage itself
you agree with that arrangement
They can refuse your request if sharing the footage will put a criminal investigation at risk.