A primary school teacher left a class of 25 pupils in tears when she told them Santa Claus does not exist.
A supply teacher told her class of seven-year-olds that Father Christmas did not exist.
The supply teacher blurted out: "it's your parents who leave out presents on Chrsitmas Day" when excited youngsters got rowdy as they talked about Christmas.
The class of seven-year-olds at Blackshaw Lane Primary School, Royton, near Oldham, Greater Manchester burst into tears and told their parents when they got home.
The parents then complained about the incident and were sent a letter by the school saying the teacher has been disciplined over the gaffe.
One father said: "My son came home and said that his substitute teacher had told the class that Santa doesn't exist and it's your mum and dad that put out presents for them.
"Apparently, they were all talking about Christmas and being a bit rowdy. She just came straight out with it.
"My lad was nearly in tears and so was everyone else in the class - especially as it was so close to Christmas. I thought it was wrong.
"He was distraught about it. He's only seven-years-old and it's part of the magic of Christmas to him.
"We told him that she did not believe in Father Christmas because of her religion and he's fine now.
"I found it shocking. She has done it maliciously.
"A lot of parents were disgusted and complained to the school. If she was a regular teacher then I think a lot more would have been done."
Angela McCormick, the headteacher, refused to comment on the incident.
Oldham Council's service director for children, young people and families, Janet Doherty, said: "This is a matter for the individual school to resolve.
"We have every confidence that the head will deal with it sensitively and appropriately."
