A survey of 70,000 teachers across England says more than one out of every three expect to quit their jobs within the next five years.
And the poll, said to be the biggest ever survey of teachers, suggests the same number are fed up with their pupils' behaviour.
A spokeswoman for teachers in England says: "Enthusiastic new teachers are fairly rapidly losing their enthusiasm."
And things may get even worse - Freya McDonald, 15, is suing her school for giving her "too many detentions".
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