Ofqual has written to exam boards this week demanding proof their qualifications are up to scratch.
The regulator has ordered boards to provide evidence their qualifications can be “trusted”, including how long they take to teach.
Exam boards will have to justify the overall time it takes to complete a qualification and, separately, the expected number of guided learning hours – time spent with a teacher.
If the qualifications are found to fall short of Ofqual’s expectations then they could be removed from league tables.
It follows a series of investigations by Schools Week revealing how schools are shifting pupils into alternative qualifications to boost league table scores.
Ian Pursglove, the regulator’s associate director of standards for literacy and numeracy qualifications, said: “Our priority is ensuring that qualifications can be trusted, are valid and appropriate to their respective level and size.
“Evidence must be provided to back up awarding organisations’ claims about their qualifications.”
Schools Week has extensively covered how schools had been advised to enter “vulnerable pupils” unlikely to get five GCSE passes into the European Computer Driving Licence (ECDL) qualification – said to be worth a GCSE.
But qualifications classed as a GCSE equivalent must include at least 120 taught hours.
Ofqual has told exam boards they now have until the end of June to justify total times for most of their qualifications, including those which are GCSE equivalents – such as the ECDL – and are approved by the Department for Education for use in school performance measures.
Ofqual has said it will start auditing awarding organisations after June to ensure “the rules are being followed”.
The regulator announced the new requirements in October to “make sure qualifications are appropriately described by awarding organisations”.