It must be legal since they all do it with impunity.
Mine obstructs every specialist recommendation eg regular iron infusions, b12 shots every 3 to 4 weeks, NDT, Creon for exocrine insufficiency, etc.
She is literally putting my health at risk and quite confident in doing so. I have NHS specialist recommendations for all the above (in writing).
I have changed nhs gps several times and they are all the same. Although invested alot of time and effort in complaining to Ombudsman and got nowhere
I just don't know how they can get away with it