Around 200 schools have escaped the threat of closure by reaching the National Challenge benchmark for GCSE results, new statistics published this week reveal.
But nearly one in seven secondaries remain subject to the controversial programme, because less than 30 per cent of their pupils achieved five higher GCSE grades including English and maths last summer.
Ed Balls, the Schools Secretary, said the results were good news. "We are on target to meet the demanding National Challenge ambition of no schools below the 30 per cent threshold by the end of 2011," he said.
But he warned the 440 secondaries still in the scheme (which offers packages of support alongside closure threats) that: "This is no time for excuses. I want every child to go to a good school and that means every school getting above 30 per cent."
Staff at St James School in Exeter were celebrating clearing the 30 per cent threshold this year, but are still angry that they were ever included.
Helen Salmon, the headteacher, said: "The timing of National Challenge was a big issue - we knew we were going to go over the 30 per cent, but now we have decided to be pragmatic and go with it - even though it has damaged our reputation. We will now use our funding to sustain our improvement."
St James's GCSE results have shot up from 17 to 32 per cent in a year. Mrs Salmon said the rise was partly due to teachers running Saturday morning classes for the OCR National ICT course, which can be worth as much as four good GCSEs. But the biggest impact on examination results was improving attendance by working with parents, she said.
Closure and conversion into an academy is one of the ultimate sanctions for National Challenge schools that fail to improve. But there are now 13 academies in the scheme, one more than last year, because of poor results. However, seven low-performing academies managed to pull themselves above the 30 per cent threshold.
One, Harefield Academy in Uxbridge, Middlesex, came under pressure when the proportion of its pupils achieving the benchmark fell from 35 to 29 per cent.
Another 12 low-performing academies were publishing their first set of GCSE results this year. The Government said this week's figures showed academies were leading the way in tackling low attainment.
Christine Blower, acting general secretary of the NUT, said: "Young people's success at GCSE is undermined by the double whammy of school league tables based both on the arbitrary thresholds of five A-C GCSEs including maths and English and the arbitrary National Challenge floor target.
"Very many young people and teachers will feel that their efforts have been belittled by these tables."
Results for 47,864 independent school pupils were included this year compared to 48,031 for 2006-07, suggesting the decline in private schools deciding to participate in the league tables is continuing. More than 200 of them now use international GCSEs, not included in government figures.
Are you a National Challenge School? The scheme originally included 638 schools because less than 30 per cent of their pupils reached the GCSE benchmark in 2007.
But this summer the Government said even if they subsequently cleared the 30 per cent threshold, the original 638 would remain in the National Challenge.
This week that changed. An official said they would be "non National Challenge schools eligible for National Challenge support".
The threshold calculation has also altered: it is now based on the percentage of pupils at the end of key stage 4 rather than the percentage of 15 year-olds.