The gap between performance in maths and English at GCSE and other subjects is rising, new figures reveal.
They show that the percentage of youngsters getting five A* to C grade passes in the three R's has fallen further behind those in other subjects since the turn of the century.
The findings come despite constant efforts by ministers to ensure schools give top priority to improving performance in the three R's. They emerge as 600,000 15 and 16-year-olds wait anxiously for their GCSE results on Thursday, which are expected to show a further rise in the percentage of pupils getting five top-grade passes from last year's 56.3 per cent.
The figures, obtained by the Conservatives, show the gap has risen from 9.2 per cent to 11.8 per cent last year.
They have prompted accusations that schools are steering pupils away from the basics in a bid to improve their exam league table ranking.
"I think what this demonstrates is that many schools are over-obsessing on the target of getting more pupils to get five A* to C grades," said Nick Gibb, the Conservatives' schools spokesman. "Instead of concentrating on a good quality education, they are trying to manipulate the subjects children take in order to boost their five A* to C grade rating.
"I don't think that's a good thing for the children's education."
The figures show there has been a steady rise both in the percentage getting five top-grade passes and those getting five top grades including maths and English. In 1996-97 the figures were 35.6 per cent with maths and English and 45.1 per cent overall. Last year they were 44.5 per cent and 56.3 per cent respectively.
Ministers have also been concerned over the lack of progress in improving performance in maths and English at GCSE. It follows research last year that showed nine out of the top 10 most improved schools for GCSE results had raised standards by putting more pupils in for vocational qualifications (GNVQs) - worth the equivalent of four GCSE passes - instead of concentrating on the three R's.
At present, schools are ranked in the league tables according to the percentage achieving five top grade passes. From this year, ministers plan to include a new ranking giving the percentage achieving five top grades including maths and English. The old measure will be abandoned after 2008.