I work for a UK company. My contractual notice period is one month.
Recently I've successfully applied for an internal post at a higher salary. My understanding is that I will start work in the new post in one months time, at the new salary. My manager says that the amount of time before I start in the new role is up to their discretion, say about 3 months. Moreover, that because I'll be working in my current role with my current responsibilities, then I'll be paid my old salary.
My questions are: is this legal and what can I do about it?