Partner called into manager's office recently to say if he keeps going the way he is and doing what he is doing, they will be looking to promote him to a senior managerial role soon.
Today, he was called back in and his manager has said if he potentially going to be promoted, he should start taking on some of the responsibilities. I think the manager is taking the piss
all the extra work with no extra money. It's basically all the hours and roles the actual manager doesn't want. 
It would be like someone being a teacher and the head asking them to be acting head a couple of times a week (doing all the jobs a head does and being accountable for things) but on a teacher's pay.
AIBU?