GCSE league tables were this week attacked as "meaningless" after the Government lengthened the list of qualifications that count towards scores used to rank schools.
Critics have said it now makes it impossible to tell how secondaries are performing in the core subjects of English and maths, just as ministers are placing emphasis on their importance.
The criticism follows controversy over the place of Thomas Telford city technology college, Shropshire, which topped this year's tables, ahead of all of England's leading private schools. It puts all students on vocational courses worth four GCSEs that helped to boost their scores.
And there were further protests as it emerged that qualifications such as an Awarding Body Consortium Certificate in cake decoration now count as equivalent to a C at GCSE. The Independent Schools Council said this meant the tables now compared "apples with candy floss", although ministers said this year's tables did not feature any candidate who had taken cake decorating.
Nationally, the proportion of pupils who got five or more GCSEs at A* to C rose from 52.9 to 53.7 per cent. St Paul's girls, in Hammersmith, west London, topped the A-level tables, with 97 per cent of its entries graded A.
Ministers highlighted the progress of specialist schools, where 57 per cent achieved the benchmark five Cs or better compared with 48 per cent in non-specialists. But four of the Government's flagship 11 academies were in the bottom 200 secondaries. Manchester academy, where 8 per cent of pupils achieved the benchmark, was second from bottom.
Phil Willis, Liberal Democrat education spokesman, said he was not criticising any school that did well, but the tables were now "totally meaningless". The Conservatives said the inclusion of more vocational subjects "simply encouraged an aim-low attitude to exams". But Stephen Twigg, school standards minister, said: "To claim this is some kind of dumbing down is old-fashioned educational snobbery."
And Nigel Florence, executive director of the Awarding Body Consortium, said: "The whole point is to recognise vocational training, which continues to be the poor relation of British education. Why is that so shocking?"
As The TES predicted in 2003, the rankings have been altered this year so that a much broader range of qualifications now counts towards a school's position.
For example, a Btec counts as. two GCSEs and a City and Guilds progression award in baking as five GCSEs at C or better. As in previous years, an intermediate general national vocational qualification is worth four good GCSEs. This explains why 149 secondaries finished with all pupils hitting the benchmark of five Cs or better. Thomas Telford emerges first overall when a further criterion is used to separate these top-performers: the average points score per pupil. For the first time this year, vocational qualifications count towards this, so a pupil passing a GNVQ intermediate scores 160 points - the same as four Cs or three As at GCSE.
Thomas Telford scored 760 points per pupil. If only GCSEs counted, this would equate to each pupil gaining 13 A*s, way ahead of the top private school, Perse girls in Cambridge. Yet, Perse outperformed Thomas Telford in most GCSE subjects.
Mr Willis said schools doing less well in the core subjects could mask their "underperformance" by entering pupils for GNVQs.
Launching his review of secondary qualifications last October, former chief inspector Mike Tomlinson said parents should be told in the tables how each school had performed in maths, English and computing. Ministers responded by pledging to emphasise English and maths. Yet it is impossible to find the percentage of pupils achieving a C or better in English or maths in the tables.
Sir Kevin Satchwell, head of Thomas Telford, said its results in science GCSE (100 per cent A*-C), maths (97 per cent), English (93) and English literature (78) should leave no doubts about its quality.
Platform, 21 Full tables at www.dfes.gov.uk performance tables