Social care in England is running as a "Cinderella service" - with the sector undervalued and its workers poorly rewarded, the National Audit Office (NAO) has said.
A new report into the adult social care workforce in England concludes that the Department of Health and Social Care is not doing enough to support the development of a sustainable workforce.
The number of people working in care is not meeting growing demand for care and the number of people with unmet need is increasing, the report adds.
The authors said that there is increasingly difficulty in recruiting and retaining staff, yet the Department does not have a current workforce strategy.
The report draws on Age UK analysis which estimated that 1.2 million people over the age of 65 had some level of unmet care needs in 2016/17.
It highlights higher than national average vacancy rates in care and an increasing staff turnover rate.
The NAO said that workers feel undervalued and there are limited opportunities for career progression.
There are around 1.34 million adult social care jobs in England and around half of care workers were paid £7.50 last year.
The last time a national social care workforce strategy was published by the Department of Health and Social Care was in 2009 - this document is only accessible on the National Archive website and mentions organisations that no longer exist, the NAO said.
The authors conclude: "The one and a half million people working in adult social care in England provide essential support to adults with care needs, yet the care sector is undervalued and its workers poorly rewarded."
The NAO has recommended that the Department produces a national workforce strategy and invests more to enable commissioners to set appropriate fees for providers, so they can pay staff adequately and afford to offer career development and training opportunities.
NAO head Amyas Morse said: "Social care cannot continue as a Cinderella service - without a valued and rewarded workforce, adult social care cannot fulfil its crucial role of supporting elderly and vulnerable people in society.
"Pressures and demands on the health and social care systems are increasing, so the Department needs to respond quickly to this challenge by giving the sector the attention it deserves and needs, instead of falling short and not delivering value for money."
Commenting on the report, Caroline Abrahams, charity director at Age UK, said: "This report is a damning indictment of the failure of successive governments to carry out workforce planning and the end result is the dangerously fragile situation we see today - one that means that in some parts of the country there are not enough care staff to give older people the support they need, even if they are willing and able to pay top rates for it.
Izzi Seccombe, chairwoman of the Local Government Association's Community Wellbeing Board, said: "Councils can't plan for the future due to uncertainty over funding and an annual £2.3 billion shortfall that adult social care will face by 2020."
A Government green paper on reforming adult social care is expected in the summer.
A Department of Health and Social Care spokeswoman said: "Everyone is entitled to good quality care and we recognise there are challenges - that's why we will shortly publish a health and care workforce strategy to address these issues.
"We've provided an extra £2 billion funding to the sector and this week announced a further £150 million for next year - in the summer we will outline plans to reform social care to ensure it is sustainable for the future."