In last Friday's Telegraph schools minister Nick Gibb wrote: 'If you look at the GCSE results since 1997 you see a dramatic increase in the proportion of C grades being awarded. Weaker secondary schools have been given an incentive to focus only on these pupils.' He added that publishing more information in school league tables (for example, data on the progress made by more able pupils) would discourage schools from 'gaming the system'.

But ASCL general secretary Brian Lightman told the TES: "While the key indicators relate to A*-C grades, schools will be bound to focus on getting as many young people as they can through the C-D border... Newspapers will continue to publish what the public are used to and can understand. Vast amounts of additional data are not going to make that more comprehensible."'

Education blogger Conor Ryan echoed this point, saying: 'The danger of trying to judge schools on a much wider range of criteria through league tables... is that the parent has more information than they can absorb, and they are unable to process it. Five good GCSEs may have been a flawed measure... but it is a simple and meaningful way of judging a school.'