Wealthy parents 'cheat the system' to win places for their children at the best schools, using a raft of manoeuvres including moving house, employing tutors, or sending children to extracurricular activities such as music or drama.
The report, entitled 'Parent Power? Using money and information to boost children's chances of educational success' was written by The Sutton Trust, which aims to promote social mobility through education.
It showed that almost a third of professional parents have moved to an area with better schools, while 18 per cent have moved to live in the catchment area of a specific school.
More than two-thirds of professional parents paid for extra activities such as weekly music, drama or sporting lessons, compared with 31 per cent of the lowest income parents.
The report also highlighted some dubious tactics employed by parents, including citing a relative's address or buying a second home within the catchment zone of a school.
One in 10 upper middle class parents admitted they had attended church services purely so their child could go to a local church state school.
Sir Peter Lampl, chairman of the Sutton Trust and of the Education Endowment Foundation, said research demonstrates that parents with money have a 'significant advantage' in school choices for their children.
He said: "This research suggests that those with money actively choose to live near good schools, employ tutors and ensure their children have extra lessons and enrichment activities that are often too expensive for other families to afford.
"This provides a significant advantage in school choice and in developing the cultural capital that is so important to social mobility and later success."
Sir Peter said that school admissions need to be fairer so that the best schools 'aren't just for those who can afford to live nearby'.
He recommended the use of ballots to ensure fairer admissions and vouchers for working class parents to spend on extra tuition, books and cultural activities for their children.
The trust also called on schools to publish socio-economic data on applications and admission.
The research, conducted by Professor Becky Francis, King's College London, and Professor Merryn Hutchings, London Metropolitan University, is based on YouGov interviews with 1,173 parents of school-age children.
Professor Francis said: "Our research shows just how far equality of opportunity is being undermined by the greater purchasing power of some parents.
"The ability for some parents but not others to use financial resources to secure their children's achievement poses real impediments for social mobility, which need to be recognised and addressed as detrimental to society."