Only 45 of the 80,000 children eligible for free school meals have gone on to Oxford or Cambridge, Michael Gove said today.
The shadow schools secretary made the claim during Commons question time this afternoon.
"Why are so many poor children being failed by Labour?" he asked.
But Ed Balls accused Gove of "statistical failings" that gave a “biased picture” of the real situation.
The schools secretary said that Gove was failing to include children who went on to study at university from further education colleges.
"I have attempted to correct you because of your statistical failings but you keep refusing to listen,” he said.
"You are only looking at children on free school meals who go to schools. You ignore repeatedly the performance of pupils on free school meals who go to further education colleges.
"Therefore your statistics always give a very unfair and biased picture of what is going on.
But Gove said his figures were correct, and it was the secretary of state who had got his facts wrong, awarding his answer an “F for fail”.
"The Association of Colleges have looked at our figures,” he said. “The 80,000 that we are talking about are all people who were in school in 2002 and whether or not they went on to school or sixth college, we looked at those who went on to Oxbridge."
And Tory MP Shailesh Vara called on Balls to apologise to the House for giving MPs “misleading information”.
But Balls insisted it was Gove who had been getting his figures wrong “time and time again” in recent months, and refused to apologise.
He denied he was accusing Gove of deliberately misleading the Commons and said the “rather large belch” of hostility from the Tory benches must be down to MPs enjoying a large lunch.
During the afternoon session the schools secretary also told MPs that he had identified £300m worth of cuts to be made to his department’s budget.
He said these included a £135m cut in the budget for education quangos and £15m from teacher training.
But his statement was cut off by the Speaker for being too long before he could name further measures.
Balls said the savings were required by the Treasury, who wanted him to reduce spending by £500m by 2013, 7 per cent of his overall budget.
But he insisted that “thanks to the generosity of the Chancellor” this would not affect “front line services”

Dods Parliamentary Communications Ltd