Parity of scale
Probably not. There has been a growth in the use of the assistant head grade for whole-school specific learning posts, particularly since uncertainty has arisen about the future of management allowances. At present, they are in limbo awaiting a decision about what will replace them. Many new assistant headships look similar to middle management posts with the difference that the new post has a whole-school responsibility for an area of work. For you to qualify in the same way, you would have to assume responsibility for something such as literacy strategy across the whole school. If that has been added to your brief, but your post has not been re-graded, you may have an issue under equal pay regulations. Contact your professional association for guidance.