In his first major education speech since taking over at Number 10, Gordon Brown said: “For those who say it is not possible, I say visit West Dunbartonshire, one of the most disadvantaged parts of Scotland.”

In 2001, 28 per cent of its pupils were entering secondary school functionally illiterate, with most likely to be in the same position when they left school. Inspired by Tommy MacKay, the noted educational psychologist, the council decided in 1997 it would have a zero tolerance policy towards illiteracy and made the audacious claim that it could eradicate the problem from its schools within a decade. Today, it is almost there. Results from May 2007 show that 97 per cent of the pupils left primary school functionally literate.

Mr Brown, however, was referring to “expected” levels of literacy. For a pupil leaving primary aged 11 or 12, that means the reading skills expected of an 11 or 12-year-old - at least a 5-14 level D or the second level of achievement under A Curriculum for Excellence.

But the bar West Dunbartonshire has set is lower. It is aiming for “functional literacy”, a reading age of nine years and six months for pupils leaving P7.

In Scotland, the 2005 Scottish Survey of Achievement on English Language showed that half of P5 pupils were already reading at the P6 level and almost a quarter were at the P7 stage. This year’s national test results in England indicated that 93 per cent of 11-year-olds had achieved a level 3 in reading, the expectation of a nine-year-old. The vast majority of primary leavers are well on their way to reaching the West Dunbartonshire goal already.

Synthetic phonics, the reading method brought back into fashion by another Scottish authority, Clackmannanshire, has been at the heart of West Dunbartonshire’s successful drive for improvement, though it is not the whole story.

Alongside the “Jolly Phonics” programme, based on blending 44 sounds into words, Dr MacKay brought in an early intervention team of 20 peripatetic teachers and targeted pupils at the top and bottom ends of primary school. For the minority of older pupils for whom Jolly Phonics has not worked, there is a tutoring scheme, Toe by Toe, which uses nonsense sounds and words to help them make the connection between symbols and sounds.

But the approach hasn’t just been about a new method of teaching literacy, it has been about changing children’s attitudes towards reading. “It is about more than the programme; it is about the people who deliver it,” said Helen Nelis, head of the early intervention team.

But Avril Davie, head of Knoxland Primary in Dumbarton, warns it might be difficult for individual schools to replicate its success. “It works because every primary in the authority does this,” she said. “It is like a common language.”