Huge new league tables showing exactly which grades every school has achieved in each individual qualification could be released by the Government as soon as next year, The TES has learned.
Ministers believe the huge quantity of highly detailed data on school exam performance will overcome any criticism that retaining vocational "equivalents" in the main GCSE league table measure diminishes their transparency.
They plan to make the expanded league tables central to the Government's drive to counter the recent "explosion" in the number of "sub-standard" vocational courses being taken in schools, flagged up in last week's Wolf report.
"We will publish as much data as possible so parents and teachers can really see what is going on in schools," a source close to education secretary Michael Gove said.
"This proper transparency will drive best practice and accountability across all schools."
But heads believe it will overload parents with information and without context could lead to false conclusions being drawn about schools.
School league tables already contain more than 40 columns of information and the introduction of exam data down to individual grades would increase their size exponentially.
But Government sources say because new technology would make the tables cheap and easy to access it would be "crazy" for the state to have the data and not make it public.
Department for Education officials are currently working on the practical details. School-by-school breakdowns of the number of pupils getting certain grades in different GCSEs will shortly be published as an interim measure.
The expanded tables represent an extension of the thinking that led ministers to trumpet new tables showing schools' detailed spending figures as the "educational equivalent" of the Go Compare consumer finance website.
Mr Gove said: "What I think people haven't yet grasped is that the greater degree of transparency we have created means that the league tables that are Government league tables are only one accountability tool.
"It is perfectly possible for others to construct their own league tables on the basis on the information we have been publishing."
But Association of School and College Leaders general secretary Brian Lightman said: "Parents don't want to audit schools.
"They need information to make informed judgments, but providing them with vast amounts of data will be counter productive.
"Raw data on its own does not tell you the full story and can lead to false conclusions."
The Government-commissioned Wolf review of vocational educational said schools should spend no more than a day a week on vocational courses.
But Mr Gove has estimated that ministers will not enforce this 20 per cent time limit.
Instead, he will concentrate on limiting the number of vocational courses that count towards league-table performance measures.
"It is clearly the case that there are some vocational qualifications which should count in what I call the anchor measure - the 5 A*-C (GCSEs), including English and maths, league table," he said.
"We are now going to try and identify which they are."
No details have been given of what criteria will be used and how long this could take.
Sources are hinting that existing qualifications could be changed so that they qualify.
Last year it was widely reported that the Conservatives, then in opposition, wanted to strip vocational qualifications out of league tables altogether.
But sources say this was never the case and that the intention was to end "equivalence" columns that saw lots of qualifications lumped together.
Now they want tables to make clear which individual vocational qualifications have been used by schools.