Disadvantaged children in Barnsley are among the least likely in the country to get five good GCSEs, according to a new report by Ofsted.
The inspection body looked at the impact of the Pupil Premium, a flagship Coalition policy strongly backed by Nick Clegg and the Lib Dems, which aims to target extra cash at pupils from difficult backgrounds.
They found its success rate was patchy - with some areas like Barnsley still failing to close the gap between rich and poor pupils.
During the next school year the scheme will distribute £2.5 billion across the country - with an average sized secondary receiving around £200,000, the equivalent of five full time teachers.
The cash is most frequently being used to pay for extra teachers and teaching assistants who give individual help or small group tuition, usually in English and maths.
The report says some authorities particularly in London are bridging the gap, with 60 per cent of disadvantaged youngsters making the grade at GCSE.
But Barnsley had the third lowest proportion of eligible children getting five or more C grades in 2012, and attainment declined further to make it the lowest attaining authority in 2013.
It concludes: “It cannot be right that the likelihood of a child receiving a good education should depend on their postcode or economic circumstance.
“Government should focus its attention on those areas of the country that are letting poor children down.”