More than one in 10 primary teachers has never read a whole book to their class, a survey has found.
And three-quarters of teachers - rising to 84 per cent of heads - say bite-size reading is destroying children's concentration, the poll by publishers Heinemann found.
Michael Rosen, former children's laureate, is backing the call for teachers to use more whole books and fewer extracts in class.
He said: "Many, many teachers want to break free from the straitjacket of Sats and the old National Literacy Strategy but have a legacy of 10 years of their expertise being undermined.
"It is not about attacking teachers - it is about attacking the situation.
"Teachers may not have a school library service because it has been wound down. There may be no school librarian. Maybe they have no time in the day where children can browse and discover books to read. Teachers may not read children's books themselves.
"It's a crying shame, and it's a form of discrimination. It is discrimination if children come from a home where they are not reading regularly, and a school is not providing that opportunity. It is discrimination if the education system is failing to provide an environment in which every child can read widely and often."
Heinemann polled 516 primary teachers - including 69 heads - and 1,000 parents; 12 per cent of teachers said they never read a whole book to their class, but the poll also found that on average teachers read 2.7 books per year to their pupils.
Six in 10 primary teachers and 72 per cent of heads said a return to whole-book reading in the classroom would have real academic benefits.
Books that teachers left unfinished included The Lion, the Witch and the Wardrobe, Treasure Island and Goodnight, Mr Tom.
Mary Hamley, of Heinemann, said: "Imagine if you were reading The Lion, the Witch and the Wardrobe but never found out what was behind the wardrobe door.
"If children have a good experience of reading with teachers in the classroom, that experience is likely to get them reading for pleasure on their own."
The firm has launched a whole-books teaching programme called Literacy Evolve. It uses three items a year - either books or short films.
Favourite authors such as Michael Rosen, Anthony Browne and Eoin Colfer are included in the scheme but there is no Roald Dahl.
Ms Hamley said: "Roald Dahl is a brilliant author but he is already there and we felt teachers didn't need us to recommend (him)."