Can your employer increase your working hours without consulting you?

[anotherharboroughfox]

 

I'm contracted for 18 hours a week and up until recently was doing 22 minimum every week. The other day I just told my employer I can't do any more for the next few weeks because I've got my A-Levels coming up, he said that was fine. So a) think of the extra money and get in your managers good books or b) just have a word with him. 

 

or her...