A cross-party commission should be set up to examine the reasons behind the UK's very low social mobility, an education charity says.
The Sutton Trust believes early years education is vital
The Sutton Trust says the government's education policy has failed to give poorer children the chance to improve quality of life.
Its founder Sir Peter Lampl says the problem "goes beyond party politics".
Tory leader David Cameron backed the call for a commission, saying there was "a problem of fairness" in the UK.
Sir Peter said: "Both Gordon Brown and David Cameron have acknowledged the seriousness of this issue, but our low level of social mobility is a problem that goes beyond party politics.
"It is a national issue which requires a national solution. We urgently need an independent cross-party commission to examine why our record is so poor and how we can address this."
The study found that children born in the 1950s had a better chance of escaping poverty than those born in 1970.
The decline in social mobility seen during the 1970s and 1980s has now flattened off, the report concludes, but shows no sign of reversing.
The UK comes bottom of the table of developed countries for which there is data available, it adds.
The report coincides with a series on BBC Radio 4's Today programme, Humphrys on Class, looking at issues surrounding the divide between the rich and poor in Britain.
The research for the Sutton Trust was carried out by the London School of Economics (LSE).
Professor Steve Machin, from LSE, said: "We had a very big expansion of the higher education system in the late 1980s and early 1990s, but contrary to many people's expectations this actually reinforced social immobility."
He said people at the bottom of the "income distribution" were ill-equipped to take advantage of the greater opportunities.
Speaking on BBC Radio 4's Today programme, Mr Cameron said: "To me it's a problem of fairness, because if people aren't achieving according to their talents, according to their potential, it's a huge waste for them, it's a huge waste for society, but it's also deeply unfair."
He said the "absolute driver of social mobility" was education and recommended the building of more schools, including city academies.
The Sutton Trust says better provision of early years education is needed to prevent children falling behind by the age of three.
It also wants to "democratise selection" at independent schools, deciding access by lottery and funding places for poorer children who cannot afford the fees.
Meanwhile, a separate report by the Economic Research Council concluded that education should be made more competitive in order to reward talent.
Based on "intergenerational earnings elasticity"
Compares children's earnings with their parents
A close correlation indicates little change in social standing between generations
The council says more children from wider social backgrounds should have the opportunity to attend cheaper private schools and selective grammars.
It wants to see new, cheaper private schools given tax concessions from the government as well as prestigious independent schools like Eton and Harrow offering more scholarships and "lower-price" options to poorer pupils.
The study's author, Professor Dennis O'Keeffe, from the University of Buckingham, said competitive education and "the dramatically effective way it encourages, identifies and rewards talent" increased social mobility.