A government crackdown on vocational qualifications used to “game” league tables has failed to have a significant impact on their use, a TES investigation has revealed.

Ministers drew up supposedly tougher rules about which non-GCSE vocational qualifications could be included in league tables after an “explosion” in their popularity led to the number of entries rising from 1,882 in 2003-04 to 462,182 in 2009-10.

But since the introduction of the new regime this year, the number of entries has fallen by only 16 per cent compared with 2010 figures. The academic who advised on the crackdown says she is “disappointed” by the outcome.

TES has calculated that, in 2014, there were 388,383 entries from 16-year-olds to vocational qualifications that are still judged equivalent to GCSE A*-C grades and will be included in the next league tables. And, in reality, the Department for Education’s “rigorous” new criteria about which courses can count in league tables do not appear to be as “strict” as originally billed.

A 2011 report by Professor Alison Wolf, commissioned by the DfE, raised serious concerns about the use in performance tables of “vocationally related courses” deemed equivalent to A*-C GCSEs. The report warned that pupils were being entered for qualifications that were “substandard.[and] were in no sense truly `vocational’ or useful”.

Professor Wolf added that schools were using the courses to improve their league table scores rather than to benefit young people.

Under the government crackdown, individual qualifications can be judged equivalent to only one GCSE in the league tables, rather than the multiple GCSEs of previous years. The DfE also said that its new rules had led to a 96 per cent fall in the number of non-GCSE or IGCSE qualifications that can count in performance tables from this year.

But many of the qualifications now banned from the tables had very few entries anyway and government figures show the drop in entries among the rest has been marginal.

David Blow, head of a Surrey comprehensive school, said the grading of the qualifications meant there was still an incentive for schools to use them as an easier way to climb league tables. “Pupils with the same prior attainment are likely to be able to obtain a higher [school league table] points score with a non-GCSE than with a GCSE,” he said.

After the Wolf report, the government stated that league tables would recognise qualifications only if they “offer pupils proven progression into a broad range of further qualifications or careers post-16”.

Professor Wolf highlighted the OCR National science qualification as being of “special concern” because it did “not allow for progress to science A-levels”. The OCR website shows that remains the case - it notes only that the course “will support progression to an NVQ”. However, the qualification still counts in school league tables.

The government said qualifications needed to “have grades such as A*-G” to be included in performance tables; in practice, however, it is including courses that have only pass, merit and distinction grades. Another DfE rule states that qualifications can count in league tables only if they have a “substantial proportion of external assessment”, but in practice this can be as low as 20 per cent.

Professor Wolf told TES she was “surprised and disappointed” that a high proportion of the non-GCSEs still being taken were for science courses, and said she would be “concerned” if they did not provide clear progression to science A-levels. “That was not quite what I had in mind,” she said. “I was hoping what you would get was a group of vocational qualifications that were quite different from academic qualifications in what they demanded but which were truly demanding.

“Nobody outside education cares whether a qualification counts for a league table; they care about whether it has any spine to it. So if they haven’t changed much, then we have a problem.”

A DfE spokesperson said: “We have more students on high-quality vocational courses because we scrapped thousands of low-quality qualifications that had lost the faith of employers.”