Ofsted chief warns literacy standards in English schools are slipping behind those of other countries, with primary pupils leaving without skills to "make their way in the modern world".
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Sir Michael Wilshaw is expected to say today that a "no-excuses" culture needs to be created in primary schools in order to improve flagging literacy levels, saying that "headline-grabbing initiatives" have failed to work.
A new report by the schools watchdog has found that standards in English are not high enough, and that there has been no overall improvement in primary pupils' learning since 2008.
One in five children do not achieve the expected literacy levels by the end of primary school, the chief inspector will warn. He is expected to make 10 recommendations to raise standards.
At Thomas Jones School, Ladbroke Grove, west London, Sir Michael told a group of teachers and literacy experts: "There can be no more important subject than English.
"It is at the heart of our culture and literacy early on. In most cases, if they can't read securely at seven they struggle to catch up as they progress through their school careers.
"As a result, too many young adults lack the functional skills to make their way in the modern world."
He added: "We are no longer a leading country in terms of our literacy performance - others are doing better. We don't need more research or more headline-grabbing initiatives which can't be sustained.
"Good leadership is the key to good literacy in schools. Above all, this means being passionate about high standards of literacy for every single pupil, and creating a no-excuses culture both for pupils and for staff."
Last year, 45 per cent of pupils who achieved the lower end of Level 4 at age 11 did not attain Grade C in English, Sir Michael will say.
He recommended that the government considers whether Level 4 is a high enough standard for children entering secondary school.
The Ofsted report, Moving English Forward, was welcomed by the National Literacy Trust. Director Jonathan Douglas said: "Addressing the barriers to raising literacy standards must be a top priority for schools, communities and employers.
"A focus on reading, writing, speaking and listening is essential across all subjects and we support the chief inspector in his call to renew a national drive for higher standards and greater engagement with parents".
However Chris Keates, general secretary of teachers' union NASUWT, said the report failed "to set out its findings in the context of the substantial improvements secured for pupils by the skill and dedication of their teachers over the past two decades".