It is most unlikely that a Holly Bush is going to have a Tree Preservation Order on it unless you are in a Conservation Area or it is particularly large.
It’s easy enough to check with the Planning Department at the local authority who will confirm whether there is any order on this or not. It’s most unusual for small evergreens to have any kind of order on them. Very large pine trees (but not Leylandi) can have tree preservation orders on them but not small evergreen bushes or hedges. There are some hedges which are ancient or long-standing for which consent is needed to remove them.
If there was a Tree Preservation Order (extremely unlikely) your nephew should have been told but just on the off chance that he didn’t get the documentation, just ring the council they will say yes or no. They will tell you over the phone.
What you will probably find is that the tenant simply likes the bush and doesn’t want it removed.
However even assuming that in the unlikely event that there was some kind of preservation order on this tree, if it is damaging property, then the local authority will allow it to be removed although sometimes they will make a stipulation that something must be planted in its place elsewhere.
Can I clarify anything for you?
Please don’t forget to rate the service positive. It’s an important part of the process by which experts get paid.