London needs to retain teachers to provide the professional leadership its schools need, and is currently not doing so

Professor Alistair Ross

It also suggests older teachers plan to leave too, meaning the capital faces losing 40% of its teachers by 2005.

The findings are the results of a year-long study commissioned by the Teacher Training Agency (TTA) and carried out by the University of North London's School of Education.

Researchers examined the teaching force in six London boroughs - Harrow, Hammersmith and Fulham, Islington, Lewisham, Tower Hamlets and Waltham Forest.

Some initial findings, revealed last year, showed that London schools were struggling to cope with rates of teaching vacancies three times higher than the national average.

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

High house prices have been driving teachers away from London

There is some hope that, potentially, this exodus could be reduced, as teachers, along with nurses and other key public sector workers, could receive government help to find and buy homes as part of a major shake-up of the UK's housing market.

The Starter Home initiative for people living in areas where property is expensive is one of a series of proposals in the government's Green Paper on housing, which was unveiled on Tuesday afternoon.

Other findings included in the final report on teachers in London suggest that only a quarter of teachers planning to leave the city were intending to retire.

Ethnic minority imbalance

The study also indicates that London has more female teachers compared with the national workforce, particularly in the secondary sector.

And researchers have calculated that teachers from ethnic minorities account for between 4% and 8% of London's teachers, whereas children from ethnic minorities make up almost 50% of the capital's pupil population.

Project co-director Professor Alastair Ross said the research team had "serious concerns" about the medium to long-term future of London's teaching force.

"London needs to retain teachers to provide the professional leadership its schools need, and is currently not doing so.

"Unless this can be achieved, London will be ever more reliant on newly-trained teachers, and on current trends, most of these will only stay a short while in London. It is essential that we monitor whether the situation improves."

Fiona Eldridge, professional officer of the TTA's teacher supply and recruitment team, said: "The TTA recognises the need for targeted initiatives to meet specific local and regional needs and we welcome University of North London's research as a good basis for the work we are taking forward with our partners in the London boroughs."