Less than a quarter of government funding aimed at giving carers a break to go on holiday has been used in this way, new figures have shown.
A freedom of information request by the Princess Royal Trust for Carers showed that in 2009/10, primary care trusts planned to use just 23% of funding to provide respite care.
Ivan Lewis, the health minister at the time, pledged "a major expansion of and access to respite care" but as the money was not ringfenced most of it has not been used as the government intended.
"The government didn't even make carers a priority for the NHS. They didn't look to use that for carers," Gordon Conochie, policy officer for the Princess Royal Trust for Carers, said on the Today programme.
David Stout, director of the Primary Care Trust network at the NHS Confederation, replied: "What the government did ask PCTs to do is plan with local government how to meet elderly people's needs in each area.
"They do have many, many different priorities... inevitably, there's a need to meet needs as best you can in your local area."
The government's carers' strategy, which applied to England only, will provide £100 million of funding in 2010/11, following the £50 million allocated for the current financial year.
"The government has completely neglected the vital work that carers do and this report is further evidence of the scale of the problem," Liberal Democrat health spokesman Norman Lamb said.
"Labour's cuts are already biting across the NHS and their failure to cut back on waste means that it is the most vulnerable who are losing out.
"This report highlights the need for a guarantee to respite care which only the Liberal Democrats are committed to."