Children born into poor families still have only the same level of social mobility they did 30 years ago, a study has found.
The report from the Sutton Trust found the educational success of children born between 1970 and 2000 was still "overwhelmingly" tied to their parents' income.
The report was published as Ed Balls, the Children, School and Families Secretary, pledged that 10-year Children's Plan would attempt to redress social inequities.
Mr Balls said it would aim to "unlock the talents and promote the health and happiness of all children, and not just some". The plan includes extra funding for early years education for those from disadvantaged backgrounds.
The Sutton Trust report found that a decline in social mobility, which existed for children born between 1958 and 1970, had stalled. But nor was there an improvement.
The UK and the United States had lower levels of social mobility than all other advanced nations.
Researchers found that the brightest children from the poorest households lost ground in cognitive tests between the ages of three and five, while those from the richest homes made gains.
Researchers said if the trend continued, the least able children from the most affluent families would overtake the brightest children from poor families by 7.
At degree level, 44 per cent of the people from the richest 20 per cent of households graduated in 2002. Only 10 per cent from the poorest fifth of households made it to university and stayed the course.
Sir Peter Lampl, chairman of the Sutton Trust, has called for an independent commission to review the underlying causes.
"Shamefully, Britain remains stuck at the bottom of the international league tables when it comes to social mobility," he said. "It is appalling that young people's life chances are still so tied to the fortunes of their parents, and that this situation has not improved over the last three decades."
The Sutton Trust is planning an international summit on social mobility next summer.
Recent Changes in Intergenerational Mobility in Britain, by Dr Jo Blanden and Professor Stephen Machin can be found at www.suttontrust.com.