I'm a secondary school teacher in a "converter" academy, and I currently work part time 3 days a week. My Subject Leader/Line Manager has been working on the timetable for next academic year, and today has told me that the days that I work need to change. He is not giving me any choice in the matter. It's because of my subject specialism and the way the blocks are for the next academic year. This is exacerbated by my subject being understaffed.
Can the school do this? Just change my days without my agreement?