A group of research experts have claimed that new league table figures prove that the "excessive" use of vocational equivalents is artificially improving the results of England's academy schools.

Dr Terry Wrigley, a school improvement expert, has claimed that 69 per cent of academies rely more heavily on so-called 'weaker' GSCE subjects than the average school.

"This seriously inflates the attainment figures for academies, compared with all schools nationally, creating a false impression that they are successful," he explained to people seeking teaching jobs and others.

Earlier this week, the government announced that it is to downgrade the value of vocational qualifications, which it claims have only served to distort league tables and mislead parents.

Alison Wolf, professor of public sector management at King's College London, claimed that the system created "perverse incentives" for some schools.

Education secretary Michael Gove, meanwhile, observed that the changes could help to transform the lives of the hard-working pupils.