Britain’s beleaguered secondary headteachers, struggling to cope with staff shortages, are plugging the gaps any which way they can.

And as desperate times call for desperate measures a secondary modern in the South-east, short of three teachers, and facing an inspection, is looking to “borrow” staff from other schools.

Elsewhere in the country, GCSE courses have been cancelled, and exam classes are taking place in lunchtime and after school, as timetables are torn up and rewritten.

Many heads are now back in the classroom themselves and, along with other senior managers, often supervise several lessons at once as classes are doubled up.

John Dunford, general secretary of the Secondary Heads Association, said:

“This illustrates the super-human efforts of heads and senior managers to keep schools running.

“But the lack of qualified teachers has clearly reached the stage where it is affecting the quality of education and must put at risk the Government’s improvement agenda.”

Heads in the survey said pupil behaviour was deteriorating and complained about both the quality and quantity of supply staff amid warnings that standards will inevitably suffer. Morale is low, goodwill is fading fast and increasing numbers of teachers are taking sick leave as stress levels and workloads soar.

In-service training is being abandoned or restricted, school improvements shelved and parents are now complaining about lack of continuity and progress.

The TESSHA survey of 876 secondaries last month identifies 2,410 teacher vacancies in England and Wales. If this was typical of all 3,800 secondaries it would mean they need to fill almost 10,000 posts.

Heads are adopting a number of coping strategies - awarding temporary contracts, switching teachers between subjects , using unqualified part-timers and even employing unqualified staff.

Biologists are teaching maths, technicians are taking technology lessons and at a south-eastrn comprehensive a geography teacher is taking French and German studies - in English.

Ministers claim that 99 per cent of teacher posts in England - and 98 per cent in London - were filled last month with either temporary or permanent staff.

What that means in practice is that at a comprehensive in the North-west, 210 lessons a week are being “taught” by temporary supply teachers. According to the headteacher: “Poor behaviour develops with temporary staff and this carries on into other lessons placing a burden on permanent staff.”

At a Leeds comprehensive, a number of pupils have not had a permanent teacher in technology since October 1999, in RE for nine months and in English since September 2000.

Meanwhile, at a north-eastern comp, some pupils rarely have a lesson with their timetabled teacher, even where he or she exists. GCSE pupils at one school in the North-west have had five science teachers for key stage 4.

The head of a comprehensive in the South-east said: “Patching and making do has become the order of the day.” His school is short of eight teachers, including three English specialists.

Another comprehensive in the region was forced to ask 30 pupils to give up a GCSE part way through the course because it had no teacher.

The crisis is not just hitting state schools. A private school in the South-east has been unable to fulfil its requirement to appoint a Catholic head of RE. None of the four Catholics it interviewed was suitable. It has now appointed a non-Catholic.

Another private school in the South-east cannot find either a classics or an ICT teacher. “Pay and conditions are generally better than offered in the maintained sector but we do not even get applicants, let alone good applicants, for a number of posts,” said the head.

TEACHER VACANCIES BY SUBJECT English 413

Maths 383

Science 375

Technology 254

Languages 252

ICT 110

Religious education 97

Special educational needs 94

Music 84

Business studies 82

PE 73

Geography 59

History 55

Art 51

Drama 23

Dance 5

Total 2,410