The Education Minister, Estelle Morris, has acknowledged that many schools are facing a recruitment crisis.

Her admission followed the release of a letter from the education authorities in Essex, warning that many headteachers are 'demoralised and frustrated' by their inability to secure the staff they need for the new term.

A senior Education Officer in the county, Nigel Hunt, told the World at One that he couldn't rule out the introduction of a four-day week in extreme cases.

The letter, addressed to the Education secertary, David Blunkett, points out that the number of vacancies has increased sharply, and the turnover of staff in secondary schools has risen by almost 50%. Even if children don't miss lessons, the problems are having 'a significant impact on the quality of education' offered by the schools.

Essex says its difficulties are compounded by having London as a neighbour, where higher rates of pay are available.

School's out

In Swindon, meanwhile, one headteacher has drawn up a contingency plan in case he can't recruit two more staff by the end of this week.

John Wells, head of the 900-pupil Headlands Secondary School, was six teachers below strength before Christmas. Even now, he believes it may be necessary for some children to lose two lessons a week.

Mr Wells says that Swindon, which enjoys almost full employment, has too many other jobs on offer with better pay, conditions and working environment. And when he tried to recruit new staff from the Midlands, potential teachers told him they couldn't afford the cost of housing.

It was, according to Mr Wells, the worst crisis of his 17-year career. Chris King, from the recruitment company Timeplan, said that Britain was not alone in experiencing these problems. Teacher shortages tended to coincide with periods of economic prosperity - and there had been two similar occasions since the war - in 1970 and again in 1980. Mr King believed it would be increasingly difficult to find people to work in the public services.

Estelle Morris accepted that there were long-term trends at work. But she said that the Government's measures to boost the pay of trainee teachers had produced a record number of new entrants to the profession.

In the short term, however, any school contemplating a four-day week had been told to contact the Department.