All children would be expected to pass reading tests at the age of 6 under a Conservative government, David Cameron will announce tomorrow.

The party would scrap the Key Stage 1 English exam for children aged 6 and 7 and replace it with a reading test that all children, other than those with severe learning disabilities, would be required to pass. Children would be taught reading by extending the use of “synthetic phonics”, which focuses on teaching the sounds that make up words. Those who failed the new test would be given extra attention, but a Tory spokesman said that it was not intended to make pupils repeat a year.

The announcement has been criticised by teachers’ leaders for being too demanding. The National Primary Headteachers’ Association criticised the move towards a reading test at the end of Year One. Chris Davis, a spokesman for the group, said: “It flies in the face of international evidence that suggests children do better if they start formal education later on.”

Steve Sinnott, general-secretary of the National Union of Teachers, said that synthetic phonics was useful but that the Tories were obsessed with it.

The Conservatives point to figures which show that, after seven years of primary education, one in five children is still struggling with literacy, increasing to 40 per cent among pupils eligible for free school meals.

Michael Gove, the Shadow Children’s Secretary, said that children of high ability from poor backgrounds were overtaken by children of lower ability from richer backgrounds at primary school. The gap widened as they passed through the system.

“The primary aim will be to make opportunity more equal,” he said. Ed Balls, the Schools Secretary, said that the national curriculum advocated systematic phonics, and Ofsted has agreed to this being implemented. Mr Davis said that the emphasis on teaching reading skills to children as young as six contrasted with the situation in many countries in Europe, where such skills are taught at a much later age. He said evidence suggested that children who learn to read later catch up and overtake early starters.

“The key thing is that they start formal work later. The evidence suggests that if children start at four that is fine, as long as the first couple of years is focused on structured play.”

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