The Tories stood accused today of being "totally out of touch" after claiming more than half of girls in the most deprived areas fell pregnant before their 18th birthday.
Conservative leader David Cameron faced embarrassment over the assertion, in a dossier attacking Labour's record, as he was trying to establish his "progressive" credentials.
He and Tory chairman Eric Pickles will today launch a new poster campaign designed to reach out to voters who would not usually vote Conservative.
The party released a 20-page document yesterday detailing what it called "Labour's Two Nations" and the disparity between the life chances of rich and poor.
But the strategy was set back when it emerged that figures on teenage pregnancy in the poorest areas were vastly exaggerated.
It claimed that the conception rate among under-18 girls in the 10 most disadvantaged areas was 54%. The real figure was 54 per 1,000.
Labour pointed out that even that figure had fallen from 60 per 1,000 in 1998.
Children, Schools and Families Secretary Ed Balls said the "dodgy" figures were an insult to communities and called on the Tories to withdraw the document.
"David Cameron's latest deception and airbrushed statistics cannot conceal the fact that the Tories haven't changed," he said.
"They are totally out of touch and have nothing to say on the important issue of reducing teenage pregnancies except smears and distortions."
A Conservative Party spokesman said last night: "A decimal point was left out in a calculation.
"It makes no difference at all to the conclusions of a wide-ranging report which shows that Labour have consistently let down the poorest in Britain."
Labour also disputed Tory claims that fewer than 50 children receiving free school meals a year won places at Oxford and Cambridge universities each year.
According to the Tories' analysis, only 45 children receiving free school meals get into Oxbridge.
By comparison, an average 82 pupils a year went on to Oxbridge from just one leading independent school, Westminster.
Shadow schools secretary Michael Gove said the figures demonstrated the extent of "Labour's education failure".
"The very poorest pupils have been let down by a school system that simply is not good enough," he said.
"Standards are falling, discipline problems are rife, and headteachers are increasingly being micromanaged by Whitehall."
Schools minister Vernon Coaker accused the Tories of using "misleading" figures about free school meals to "distort and do down the achievements" of state school pupils.
He said data on free school meals was not collated for students at FE colleges, where young people from lower income families were more likely to take their A levels.
The Tories insisted the figures were accurate.
In the foreword to the "Two Nations" document, Mr Cameron said: "Labour's great claim is that they are 'for the many, not the few'.
"That rings hollow today. This report exposes the truth: after 13 years in government, the party that prides itself on fairness has delivered the very opposite.
"Labour have failed the poorest in our society."
He added: "If we're going to bridge the divide that separates Labour's two nations, we need to treat the root causes of poverty - that chain of deprivation that runs through family breakdown, educational failure, worklessness and debt."
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