Successful students are three times more likely than low-achievers to be given textbooks of their own, a new survey reveals.
Researchers found teachers were prejudiced against weaker students - even though they would benefit most from taking books home.
The Keele University study shows only 20 per cent of pupils from low-attaining schools were allowed to take home a science text or course book. At high-attaining schools, 65 per cent could do so. In modern languages, high-achievers were given twice the opportunity, at 85 per cent compared with 45 per cent, and in history, 36 per cent compared to 15 per cent.
Researcher Professor Margaret Maden said reasons for this appeared to be largely prejudicial. Teachers were worried about books being damaged or lost, and at low-attaining schools were more reluctant to give them out.
"But you could argue that the more disadvantaged you are, the more you deserve them."
One London school had a policy that no children were allowed to take books home. Further questions needed to be asked to explain this "stark" correlation between access to books and attainment, she said.
Eighty two per cent of headteachers and subject heads believed textbook availability was linked to higher achievement.
In the rush to raise standards the Government, the Office for Standards in Education and teachers were ignoring the need for all pupils to have their own textbooks, Professor Maden said. Taking books home allowed pupils to catch up on work they missed or failed to understand in class.
The survey of 2,800 Year 8, 10 and 12 pupils showed half of all GCSE students had to share national curriculum textbooks, a problem, they said, which held them back at school.
More than 80 per cent of pupils surveyed believed sole access to a textbook helped them in their studies.
Professor Maden urged schools to gather figures on how much they spent on books, saying the need for textbooks had been sidelined.
"It's partly under-funding but it's also a matter of priority both at national and school level.
"Only one in four Year 8 pupils in some subjects can take textbooks home and nine out of 10 parents believe their children's school has too little funding for textbooks.
* World Book Day (April 23) has a telephone helpline for schools on 01634 295585 for help with voucher queries and bookshop addresses.