Research commissioned by the Teacher Training Agency has found that vacancies are not being filled and many teachers are leaving the profession altogether, leaving schools to depend on temporary agency staff.

A survey of six London boroughs, carried out by the University of North London, has found that schools are still facing problems with recruitment and retention. In shortage subjects such as maths, almost half of vacancies remained unfilled in the year of the survey.

Although London boroughs have always faced a high turnover of teachers, the survey found that retention problems in the boroughs - Hammersmith and Fulham, Harrow, Islington, Lewisham, Tower Hamlets and Waltham Forest - were exacerbated by a growing number of staff who were leaving teaching altogether.

Internet recruitment

Over a fifth of teachers leaving posts in London were leaving the profession, with bad behaviour by pupils and the lack of promotion opportunities among the most prominent reasons for leaving teaching.

Among staff who were moving to other parts of the country, teachers identified high housing costs, crime and pollution as reasons for leaving the capital.

A project to recuit more teachers for London schools was launched in April by the Schools Minister, Estelle Morris, with an internet site which promoted the benefits of living and working in the capital.

'Teachers for London' encouraged would-be applicants to consider the thriving cultural life of the capital, rather than its overcrowded streets and high cost of living.

The problems in London come as the recruitment crisis across the country appears to be diminishing. The government's scheme of cash incentives - offering �5,000 for student teachers in shortage subjects - has pushed up applications for teaching maths by a third.