Children as young as four will be tested to identify the brightest pupils, if Labour are elected to a third term in government.

Ruth Kelly, the education secretary, said that she wanted teachers to choose the most able five per cent of pupils for special attention at primary school.

Kelly said the move would help to tailor education to individual need.

"To support young children struggling to keep up, we will introduce a programme of concentrated catch-up help, targeted at those lagging most behind, especially in reading, at key stage one," she said.