The benefits created by London Challenge, a scheme that has helped transform the fortunes of the capital's schools, risk being lost if ministers end it in 2008 as planned, inspectors have warned.
Ofsted has found that standards in London have risen "dramatically" since 2000, outpacing similar schools around the country.
The five-year scheme played an important part in that success, according to the report published this week. Inspections showed that last academic year, the proportions of London secondaries judged to be good or better were higher than the national averages. Between 2000 and 2005 they had been significantly lower.
But the inspectors warn: "The successes to date demand that careful consideration is given to the risks when London Challenge ends in 2008. As certain schools and local authorities have improved, others requiring intensive support have emerged.
"London Challenge has been able to respond to this quickly. This may not be the case in 2008 when the project finishes."
Lord Adonis, minister with responsibility for London schools, told The TES that the Government was considering extending the length of the scheme and broadening it to cover other areas of the country, as Ofsted also suggested.
The schools watchdog said the London Challenge's combination of political leverage, resources and expert advice could be considered in other areas of England. But the minister said there was a danger of diluting its success.
He said:"We are clear that one of the reasons for successes of the London Challenge was the focus on London secondary schools, including a dedicated team in the department, a minister and a chief adviser. One of the issues is how can we extend the scope to other cities without losing that focus."
Continuing the scheme in London beyond 2008 would be considered. But there were "cost issues" and he thought many of the improvements would continue anyway. Ofsted compared schools where less than 30 per cent of pupils had achieved five or more A*-C GCSEs in 2003. In inner London, 89 per cent of them had improved their performance between 2001 and 2005; in outer London, the figure was 85 per cent. This compared with 73 per cent across the country.
pound;40m help for capital
The pound;40m scheme was launched in 2003.
It has targeted advice and resources at 70 particularly poorly performing secondaries and the boroughs of Haringey, Islington, Hackney, Southwark and Lambeth.
Extended to primaries last September.