Not sure. It appears they are legal to own in The UK if you have a firearms certificate.
I am sure there be some in various Army Cadet and Air Training Corps buildings in the 80's and 90's. They definitely were in the late 70's or there was access to them. The rifle(s) was kept locked in one place and the bolts somewhere else IIRC. I think they did not have a magazine fitted. I do not know if they could if need. The .22 rifles which looked similar did not. Again IIRC I fired a Martini Henry carbine (?) as well that was .22.
But it was about 45 years ago! I remember missing the target with the .303. I tensed up too much. I was much better with the .22. Never 'a marksmen' but I hit the target.
In 'the real world' the Canadian Rangers (who I think feature in a T2K article) were using Lee Enfield's until 2016 according to this:
https://en.wikipedia.org/wiki/Lee%E2%80%93Enfield#Users