The Education Secretary refuses to use the word "crisis" but teacher shortages in England and Wales have more than doubled since last September. A survey by The TES and the Secondary Heads' Association suggests nearly 10,000 permanent jobs were unfilled in secondary schools last month.
Supply agencies admitted they are unable to fill at least 20,000 temporary vacancies a week, and headteachers have warned of increasing numbers of exclusions as behaviour deteriorated among upils.
David Blunkett admitted that the situation was serious but added: "The word crisis is the kind of word you use when you have foot-and-mouth disease destroying an industry. It is not a word you use when you want to resolve a problem by recruiting or bringing back more professionals."
A junior school in Mr Blunkett's Sheffield constituency has sent pupils home for lack of staff, sparking a frantic search by his departmental officials for supply staff.