Ofqual has ruled out making changes that could have rationed the number of A and A* grades awarded in subjects attracting the brightest pupils.
The exams watchdog's decision today follows more than a year of public discussion and debate on a series of measures proposed by Ofqual to improve the comparability of grades across GCSE and A-level subjects.
It said it will not try to align grade standards across the full range of GCSE and A-level subjects as the challenges are too great.
One-off measures in 'compelling' cases
One of the proposals Ofqual had considered was ensuring that the same proportion of students would gain each grade in every subject to make exam results in "hard" and "easy" subjects more easily comparable.
Currently, some subjects such as further maths, classics and physics see a much higher proportion of pupils receive top grades than others, including design and technology, computing and drama.
But today Ofqual said it will "not try to take co-ordinated action to align grade standards across the full range of GCSE or A level subjects" as there were too many challenges in measuring how subjects may compare.
The exams regulator did say, however, that it will consider making one-off adjustments to standards in subjects where there is a "compelling case".
For example, it has already begun conversations with subject communities in relation to A-levels in physics, chemistry and biology, as well as modern foreign languages.
But Ofqual did announce that it will ensure standards are set appropriately for French, German and Spanish at A-level after new research concluded that awarding should take into account the fact that native language speakers take these subjects.
'Grade standards should be comparable'
The research was conducted in response to concerns that the proportion of native speakers sitting A-level MFL is rising and that, as a result, students are being disadvantaged due to the methods via which standards are maintained.
The adjustment to grade standards, which will be decided in the summer, could lead to "small increases" in the proportion of A-level MFL students getting top grades if the ability of the cohorts remain the same as previous years.
Sally Collier, chief regulator of Ofqual, said: "Everybody expects that grade standards between exam boards in any particular subject should be comparable.
"However, inter-subject comparability is more difficult to consider. We are extremely grateful to the stakeholders who have offered their opinions and the many researchers who have helped us reach our policy decision.
"Combined with the actions we are taking this summer specifically in relation to A level languages, it will mean we are better placed than ever to ensure standards in GCSEs, AS and A levels are appropriate."
Want to keep up with the latest education news and opinion? Follow Tes on Twitter and like Tes on Facebook
For all the latest news and views on A-levels, visit our specialised A-level hub