History is dying out in academies as teachers stop running it as a separate subject and push children towards "easier" vocational courses to improve their rankings in the league tables, according to new research.
Less intelligent children are being banned from studying history by schools desperate to improve their exam grades according to the Historical Association.
Only about half of academies involved in the major survey now run history as a separate subject and increasing numbers of pupils are denied the opportunity to keep on studying it after the age of 13.
Teachers in a third of the academies that took part in the surveys said they had seen GCSE uptake decrease; they also reported widely fluctuating numbers taking the subject.
Only about 17 per cent of secondary schools reported a fall in exam entrants and teachers said GCSE numbers were stable.
Teachers advising pupils to do a diploma or BTEC are helping to kill off the subject, the study warns.
One academy teacher told the researchers: "History is seen to be too academic. Entrance to the course is based on Fischer Family Trust predictions, and students who are predicted lower than a B are not allowed to study the course.
"We are also not allowed to run `entry level' GCSE courses for students with specific needs, as that is not thought to be meeting the attainment targets for the academy."
History is disappearing from the curriculum in a "rapidly increasing" number of schools, particularly in Year 7 when many secondaries adopt primary-style lessons. But an alternative curriculum based on skills is not always successful, according to the association.
Of the schools that have seen a fall in numbers taking GCSE history, a third said this was because the subject was in "competition" with others - including those viewed as easier or offering more "value" for the school - for example, qualifications worth four GCSEs in PE, ICT and media studies. Teachers said pupils also perceived the subjects as easier to pass.
Rebecca Sullivan, chief executive of the Historical Association, said this is because many children are being advised to do other subjects in case the school's GCSE results suffer.
"Staff are steering them away from history if they are not predicted to get a reasonable grade," she said.
"This is a real shame because we have found 69 per cent of pupils really enjoy the subject."
The study found "strong indications" of coercion among lower-achieving students, which effectively barred them from continuing with history.
One teacher said: "Students have been deliberately denied an opportunity to study history by forcing them down vocational or academic pathways.
"GCSE students have also been taken off courses against their wishes to do BTEC qualifications in six months so that the school can boost its position in the league tables."
About 700 teachers in 644 schools took part in the survey - which includes 503 comprehensives, 36 grammar schools, 23 academies and 82 independent schools.
David Laws, the Liberal Democrat education spokesman, has written to Ed Balls, Schools Secretary, and Ofsted asking them to investigate the issue urgently.
A thing of the past?
Of the schools who took part in the survey, only 59 per cent of academies ran history as a discrete subject, compared with 75 per cent of all schools, 94 per cent of grammar schools and 72 per cent of comprehensives.
Almost one-third of the comprehensive schools and over half of the academies reported the amount of time allocated to history had dropped since the previous year.
There is a "statistically significant" relationship between the amount of time allocated to history in Year 9 and numbers of children choosing to study the subject at GCSE level.
About 5 per cent of schools said children now started GCSEs a year early - and consequently pupils could lose a year of history teaching if they didn't choose it as an exam subject.