Protected? Not all Scotch pines are protected. The law is the same concerning Scotch pine as it is for other trees
Plainly you are not allowed to kill a tree which is not yours unless you act under the instructions of the owner. Even if you do own it ,it may be protected.
It'll be protected if it is itself subject to a Tree Preservation Order (TPO) or part of a group of trees e.g a tree belt or wood that is subject to one. It'll be protected if it lies within a conservation area. It may be protected by some clause in any lease you have, your property being leasehold. It may even be protected by a condition in your freehold. title
, quite apart from any TPO that exists.The local council will advise you whether or not a given tree is protected in any way by any statutory protection (TPO, Conservation Area etc). There may be other specific protections, but those are the ones that come to mind.
Why though, do you want a dead pine tree standing?It's highly likely to present a hazard when it's dead.That may mean that you'll end up being sued.