Fewer schools were successful at finding a new head despite a smaller number of vacancies during 1997-8, according to a study carried out by Education Data Surveys.
The re-advertisement rate in primaries was 28 per cent - at 4 per cent the largest year on year rise since the 1980s - and in secondaries 19 per cent, two percentage points more than last year. London has the highest rates, with 60 per cent of jobs having to be readvertised. Primary schools with poor key stage 2 English results fared badly in attracting a head.
John Howson, author of the report, said the figures are very serious. He predicted the Government's policy to make the National Professional Qualification for Headship compulsory by 2002 would make the situation worse.
David Hart, general secretary of the National Association of Head Teachers, said too many schools do not have headteachers and in some parts of the country agency staff, many from overseas, are propping up the system. "There are many cases of staff who are not teaching their first subject," he said.
John Dunford, general secretary of the Secondary Heads Association, said the pool of potential heads had been diminished by the rush of early retirements in 1997.
"We clearly have a crisis both in primary and secondary sectors." Headship, he said, is now seen as a high-risk job.
The survey, based upon job adverts in The TES and daily paper education sections, showed the most common reason given for failure to appoint first time round was a shortage of applicants.
* The survey paints a more serious picture than a separate study carried out by the School Teachers' Review Body, which found 99 per cent of schools felt new appointees were well or adequately matched to the post.
On average, advertisments for all teaching posts received 14 applications and about four candidates were interviewed. There are some pockets where recruitment is more difficult, for example inner London schools, special schools, and in shortage subjects, such as physics, technology and music.
Music and modern languages received 10 or fewer applicants on average and one in 20 posts was not filled.
About 800 schools had acting heads and 1,500 had acting deputies. Advertised primary headships received relatively few applications. However secondary headships received more applications than any other type of post.
Overall 10 per cent of posts were advertised at the start of the autumn term - 65 per cent were for permanent jobs, the rest temporary or fixed-term contracts.