The school curriculum is being "hi-jacked" by political agendas, claims a think-tank.
Has geography jumped onto an eco-bandwagon?
Science lessons are becoming debates about global warming and GM crops, rather than objective science, says the Civitas report.
In English, pupils can miss out on classic writers and are steered to more "relevant" modern writers.
The government rejected the report as a "profound misunderstanding" of the school curriculum.
The think-tank report argues that the curriculum has been "corrupted by political interference" - with lessons manipulated to promote causes such as "gender awareness, the environment and anti-racism".
Rather than delivering impartial information, the Corruption of the Curriculum report argues that too many lessons have an ideological message - and that pupils are missing out on academically-rigorous lessons.
The way science is taught has "more to do with media studies than hard science", claims the report - with accusations that it has become a place to debate issues such as nuclear power, rather than learn objective scientific facts.
In history, the report claims that pupils are "taught through a filter of politically-correct perspectives" - which fails to give them a meaningful, chronological grasp of the narrative of history.
Geography is accused of getting onto the environmental bandwagon and failing to arm pupils with enough information to form their own independent opinions.
Schools Minister Jim Knight attacked the report, saying it was "insulting to the hard work of pupils and teachers to claim that the education system is just a political football in order to promote political or social goals".
"A curriculum which reflects the world in which we live helps to engage children in learning, but it does not follow that teaching and learning is less academically rigorous," said Mr Knight.
"The Civitas report appears to be based on a profound misunderstanding of the national curriculum and modern teaching methods," said the schools minister.
But the Shadow Schools Minister Nick Gibb described the report as a "devastating critique of the curriculum" - which exposed a trend which had been "deeply corrosive effect on standards of education".
"We've got to move away from the anti-knowledge, anti-intellectual approach of many education reformers who have been far too influential in the development of the curriculum over the last 20 years," he said.