Went to an Ofsted rated ("good") school today for only the second time covering English. Terrible period 5. Was covering a year 9 class. Was so bad I nearly called the agency to resign, but held back after taking a minute to calm down. Class made very little attempt at the work, were loud and kept interrupting during a reading aloud task (when one person should have been reading/speaking at once). Later when we did some Q and A, people just spoke over the person giving the answers. Would be easy enough with one person doing this, but more or less the whole class was speaking over me. Called SLT. They came, class goes silent. SLT member doesn't say a word to me, waits until after about 5 minutes of walking around the room, telling the children to stay focused on their work. A student was rude to him so SLT took him outside for a word. After a few minutes of silence, I decided to ask the class why they decided to behave the way they did, and why they went silent when SLT teacher came in. They said that it's because he is intimidating, scary and has authority. I asked "and I don't?" and got the usual riff-raff about me being a supply, and they can't expect the class to be good. Told them that many would disagree with that. I also told the children that I pay them the compliment of assuming that they behave well when their usual teacher is here and that I expect better if I have them again. While they were quietly getting on with their work, some of them made some polite small talk with me and were finally being respectful. Did I make myself look weak by calling SLT? Should this only be used for the removal of one student. The giving the sanctions/following policy of giving written warnings in planner did not seem to deescalate the situation. This was one of the worst classes I have had, probably the worst. I struggle with behaviour sometimes and I resigned from a long term cover post because of this previously. Maybe I should have learned from the first time.