GOVERNMENT officials do not know how many teaching posts are vacant or filled by staff on temporary contracts, it was claimed this week.
The most recent Government figures - from last January's annual statistical survey - showed more than 2,500 nursery, primary and secondary vacancies in England and Wales, up by two-thirds in two years.
But they do not include vacant posts where teachers are "acting up" or where agency or other supply staff have been recruited to plug a gap for a term or more.
This week's newspaper estimates of up to 10,000 vacancies highlighted the lack of detailed statistical information on staffing in schools in England and Wales.
Recruitment analyst John Howson said the truth was ministers did not know the exact scale of the crisis. "Government figures mask the problem, especially in the London area," he said. "The Government doesn't know in any detail how many overseas teachers there are in our schools, or how many of them are appropriately trained. But subjects like home economics wouldn't exist without overseas teachers."
David Hart, general secretary of the National Association of Head Teachers, said official figures also failed to include teachers who were taking classes that were not in their first subject. "But the Government is only too aware of the scale of the crisis and that whichever figures you believe, we are simply not recruiting enough people to the profession."
Figures for 1999 will be collected later this month, and experts expect them to show a further deterioration.
"We're finally seeing the problem of under-recruitment to training courses bleeding through into a lack of people coming out of training and into schools," Mr Howson said.
The National Association of Schoolmasters Union of Women Teachers said it was now hearing reports that the widespread use of overseas supply teachers was spreading from London to other major cities.
"All the anecdotal evidence we're getting is that the situation is getting worse," general secretary Nigel de Gruchy said.
A spokesman for the Department for Education and Employment said:
"Regardless of the difference in figures we still acknowledge there are teacher shortages. We're certainly not complacent."