Truancy, lateness and bad behaviour were rife at the 900-pupil south London comprehensive and 15 children were permanently excluded in a year.

Four heads left in as many years, staff turnover was high and results suffered. In 2000 only 11 per cent of pupils, many drawn from a deprived area of Lambeth and 85 per cent on free school meals, left with at least five good GCSEs.

But since then a mini-revolution has transformed Stockwell Park.

Judette Tapper became head in September 2000, hard-line approaches were taken to unruly pupils and a school motto - Attitude Determines Altitude - was adopted and slapped across every classroom wall.

This week the school’s progress was underlined as it registered record GCSE pass-rates. Almost half of the 150 teenagers sitting exams this year gained at least five A* to Cs and only three failed to get at least one GCSE grade.

However, the increase is likely to be viewed with scepticism by some as five new GNVQ courses have been adopted at the school in recent years - and 90 per cent of current Year 11 pupils took at least one.

The vocational subjects, which can count for four C-grades or better, have already attracted wide criticism amid claims that pupils receive too much credit for insufficient work.

Last year The TES revealed how Thomas Telford school in Shropshire made pound;7 million selling its online GNVQ courses to schools keen to move up the league table.

But Ms Tapper criticised such claims, saying they belittled pupils’

efforts. “The course suits a lot of the children’s learning styles and I think many have to work much harder on GNVQ courses,” she said.

“The GNVQs increase children’s motivation because they are more interested and focused. But we have not improved on the back of the GNVQ - we have improved because the heart of the school has been completely transformed.”

The proportion of students leaving with no GCSE passes at all is set to fall to 3 per cent - compared to 6 percent in 2000. Moji Odulaja, 16, said:

“Pupils’ attitudes towards the school have changed a lot for the better while I have been here.”