Research has found that poor children are almost one year behind the more wealthy in terms of education.

According to the Sutton Trust, the poorest children in society are, on average, almost one year behind middle-class children in their education – at the age of five, they are 11.1 months behind others in vocabulary tests.

Parenting style and the home environment contribute to half of the explained gap. For example, the study found that only 45% of children from the poorest fifth of families were read to daily at the age of 3, compared to 78% of children from the richest fifth of families.

In addition, almost half of the poorest children were born to mothers below the age of 25, two-thirds do not live with both biological parents when they reach the age of 5, and more than a third were born to parents without a grade A-C GCSE between them.

Sir Peter Lampl, Chairman of the Sutton Trust, said: “It is a tragic indictment on modern society that our children’s future life prospects depend so much on their family background, not their individual talents.

“These findings are at once both shocking and encouraging – revealing the stark educational disadvantage experienced by children from poorer homes before they have even stepped into the school classroom, but also the potential for good parenting to overcome some of the negative impacts that poverty can have on children’s early development.”

This one-year gap can be reduced by about one half if the child receives good parenting – such as regular bedtimes and daily reading – and a supportive home environment, however it can only be reduced so far. According to the report, poor children who receive the same parenting behaviours, characteristics and home environments as middle-income children are still on average three months behind.

This inequality does not appear to get any better in higher education. The Sutton Trust, which promotes social mobility through education, has also found that the proportion of non-privileged students at some of the most academically selective universities in the UK “remains depressingly low”.

For example, it found that three in every ten Oxbridge undergraduates in 2007 and 2008 were from just 100 schools and colleges, and the majority of these were fee-paying or state grammar schools.