Life chances in the UK are too dependent on parents' income, rather than education and ability, and the situation is getting worse according to a new report.
The document, published by the South West TUC warns that the UK has the joint highest level of earnings persistence – the extent to which people's incomes are associated with those of their parents – among advanced economies, along with Italy.
It also warns that the price poor people pay for a lack of social mobility is getting worse in Britain as the income gap between the richest and poorest households has widened over the last three decades.
The report, Dismantling the Barriers to Social Mobility says that while all mainstream political parties agree on the need to tackle the barriers to social mobility, their proposals vary wildly, from deregulation and lower taxes to free school meals and a stronger social security safety net.
The report analyses the UK's track record on seven key factors influencing social mobility and compares its performance to that of other advanced economies.
It highlights four factors – income inequality, childhood poverty, full-time women's employment and the link between family background and educational performance – where the UK lags behind most other advanced economies and suggests that political parties should prioritise these issues in order to make genuine in-roads into encouraging greater social mobility.
In particular, the TUC would like to see more done to increase full-time maternal employment rates through high quality flexible working and affordable childcare.
This would also tackle many of the other barriers to social mobility, such as child poverty and pre-tax income inequality.
At the same time, employers and government need to do more to reduce the pay and career penalties associated with part-time work, said the report.
With more than six million part-time workers, the UK has one of the highest rates of part-time employment among advanced economies and research shows that this can limit children's life chances, says the South West TUC.
Nigel Costley, regional secretary of the South West TUC, said: "People's incomes in Britain are more influenced by their parents' wealth than in any other advanced country.
"This lack of social mobility holds millions of people back and means that they don't get a fair share of the benefits of a growing economy, such as decent pay and educational opportunities.
"Worse still, rising inequality means that the price people pay for a lack of social mobility is getting bigger.
"But while few people in this country would argue against social mobility, successive governments have a poor track record of tackling it.
"When it comes to income inequality and full-time employment rates for mothers, the UK is ranked well below our global competitors.
"Raising the full-time employment rates for mothers is an important way to boost social mobility."