Social care in the UK will reach "crisis point" if nothing is done to improve pay and conditions for workers, a new report has warned.

A study by the Resolution Foundation think tank found that two-thirds of care jobs paid below the living wage last year, with no chance of an improvement without additional public funding.

A year-long investigation found "pervasive" low pay and tight budget constraints facing care providers.

The cost of paying the living wage to all 1.4 million care workers last year would have been £1.4 billion, from council budgets or additional national funding, but half would have been returned to the Exchequer through higher income tax and National Insurance receipts and lower benefit payments, the report said .

Laura Gardiner, senior research and policy analyst at Resolution Foundation, said: "There is a growing consensus that social care provision in the UK will reach crisis point if nothing is done to improve pay and conditions for this overstretched and undervalued workforce, who care for the most vulnerable members of our society.

"By analysing the costs and benefits of moving to a living wage for all care workers, we hope to inject much-needed clarity and realism into a debate in which some treat a living wage in care as a costless aspiration, while others dismiss it out of hand as being unaffordable and just too difficult.

"Our report aims to provide the kind of figures needed to start thinking seriously about how to tackle pervasive low pay in a sector that for too long has been overlooked by policy-makers.

"While the investment required by government to make the living wage a reality for all care workers is substantial, we believe that the wider social and economic benefits create a compelling case for action."

The living wage is £7.85 an hour outside London and £9.15 in the capital, compared with the national minimum wage of £6.50 for adults.

Unison general secretary Dave Prentis said: "This is the best evidence yet that paying a living wage would benefit care workers, those receiving care and the UK economy.

"Plans to integrate our health and social care systems are doomed to failure unless the social care system is adequately funded and care workers are paid a decent wage.

"The Government has been quick to give tax cuts to the rich. Now it's time for ministers to recognise the contribution made by almost a million dedicated workers who care for the elderly and vulnerable in our society."

Janet Morrison, chief executive of Independent Age, a charity which helps older people, said: "When so many of us will need care ourselves - or know someone who will - we have to ask whether we are comfortable with those people responsible for carrying out such vital, challenging work earning less than the living wage.

"Worryingly though, up to 220,000 are not even paid the national minimum wage. However, since low pay in the social care sector is a result of chronic underfunding, addressing it will require fundamental reform in how we pay for care."

Care and Support Minister Norman Lamb said: "We want a fairer society where everyone gets the care they deserve - to do this we need a skilled, valued and fairly paid workforce.

"We are looking at what more we can do to make sure social care workers are paid fairly, and one of our first priorities is to make sure all care workers are paid the national minimum wage to which they are entitled - that's why we are taking action to name, shame and fine employers who haven't paid the national minimum wage."