Half of teachers believe they are not knowledgeable enough to improve pupils' literacy, according to new research.
A survey by the National Literacy Trust also finds that almost a quarter of teachers do not feel confident teaching the literacy requirements set out in the national curriculum.
Jonathan Douglas, the trust's director, said teachers needed more support to help them keep up with the latest requirements. Science and maths teachers were now required to teach literacy but did not have the neccessary training, he said.
According to the survey of 2,326 education professionals, 51.7 per cent of teachers feel that a lack of knowledge of how to support literacy is a barrier to improving it in the classroom.
The research reveals that 23.9 per cent are not confident in teaching the new curriculum, while 21 per cent believe they do not have enough subject knowledge to teach it.
Mr Douglas said some teachers had been left underprepared in teaching literacy because of the changes made to the education system in recent years.
"The new national curriculum has highlighted a gap, reflected in our survey, between what is required of teachers and what they feel able to deliver," he said.
"Literacy must now be taught by every teacher, even if their specialism is in maths or science.
"A changing education landscape over recent years means that some teachers will not have been trained to teach literacy and other teachers may not even have learnt literacy at school themselves but are now required to teach it."
Liz Robinson, headteacher at Surrey Square Primary School in Southwark, South-East London, said: "This research highlights that it is a shared responsibility for teachers across all subjects to teach literacy skills. This should not be seen as a separate task, but part of the work they are already doing. Teachers need to be more confident in their own abilities to teach literacy as they know more than they think."
The research finds that 95.2 per cent of teachers believe it is their duty to promote literacy, but only 42.4 per cent say they have particular strategies for teaching it.
More than three-quarters of teachers (77.1 per cent) believe the home environment is a barrier to a child's literacy levels, while 56.6 per cent say the increase in the use of technology is a reason why fewer children are enjoying reading.