A junior school was forced to apologise after one of its teachers told children that Father Christmas did not exist.
The youngsters, aged nine and 10, were asked to put themselves in the place of Royal Mail staff and make up replies to children explaining why their Christmas requests had been rejected.
One parent said: "My wife and I make a special effort to keep the belief in Santa in our daughter's mind as we believe it adds to the magic of Christmas for her and her four-year-old brother.
"What gives the school the right to decide when children should know the truth about such a harmless matter when knowing the truth does take away that little bit of magic?"
However, another mother, Sally Jones, 32, who has three children at the school, said she was not upset by the blunder.
"The only advantage of Santa as a parent is that you have got someone to blame if children don't get what they want," she said.
Jackie Jackson, headteacher of Ladysmith junior school in Exeter, said: "The choice of this worksheet was a genuine mistake by a teacher which we are sad about.
"As a school we delight in the magic of childhood and believe that Christmas is a special time. This worksheet will never be used in the school again."