There are an estimated 6m carers in the country
The National Health Service in England is failing to invest in sorely needed services for carers, campaigners say.
Data uncovered by two charities suggested just £10m of the extra £50m earmarked for support services was being spent this year.
The money was promised by the government to help fund services such as respite care and counselling.
The Princess Royal Trust for Carers and Crossroads Care said the results of the poll of 130 NHS trusts were alarming.
There are 6m carers in the country, 1.5m of whom spend more than 50 hours a week looking after relatives.
Ministers last year acknowledged the role they were playing when they promised an extra £150m for support services.
But instead of ring-fencing the money, the government merely asked primary care trusts to set aside £50m this financial year and £100m during 2010-11 from the annual increases in the health budget.
To see whether the funds were getting through to the frontline, the two charities, which provide support services to carers, requested spending data under the Freedom of Information Act.
They received responses from 130 of the 152 trusts in England showing that 80% of the funds were not being or were not due to be spent this year.
Carole Cochrane, chief executive at The Princess Royal Trust for Carers, said: "We are alarmed and disappointed at these research findings.
"Once again, the recognition of carers and their significant contribution is not seen as a priority."
And Anne Roberts, chief executive at Crossroads Care, added: "Carers need support.
"Without a break they can often reach crisis point, where their own physical and mental health deteriorates.
"When carers reach this point, trusts will have to provide additional support at additional cost, so failure to provide carers' breaks is short-sighted."
Liberal Democrat health spokesman Norman Lamb said: "The government should be ashamed of its failure to provide the help they promised to carers.
"Many people across the country are in desperate need of this support."
And shadow health minister Stephen O'Brien added: "It is disappointing that the government, despite pledging more money to help carers, has not seen it through to the frontline."
But care services minister Phil Hope said the government was working with care charities and the NHS to ensure money was spent in the most effective way.
"Supporting carers has always been a high priority for this government."
Below is a selection of comments you have sent in regarding the issues in this story.
I have been looking after my father since 1999. When he had a stroke I moved into his house to look after him. I work full time and every spare moment is spent looking after my father, running up and down stairs, cooking and seeing to all his physical and emotional needs. I don't have holidays or breaks, because I work I am not registered as a carer. There must be many people like me, it is exhausting and has affected my health which is slowly going down hill. I can't afford to work part time or give up my job so I struggle through. I get no help from anyone including my family, as for them it's out of sight out of mind, and the same with social services.
My wife and I are both in our seventies, we care for our 46-year-old daughter who has mental health issues and a learning disability. She would like to live independently, with back up help, but we are unable to get any help with funding or help with accommodation. It would seem that we look after her too well at home. We were actually told that if we made her homeless, then help would have to be made available.
I am now a pensioner with diabetes and although I do not need a carer right now I know I will in the future. With the growing aging population we need more trained carers and volunteers to help. This is very important.
S Kelsall, London
I am the sole full time carer for my husband - who lives with bi-polar disorder - and to hear reports that the NHS is holding back on spending a huge £40m earmarked for supporting carers has shocked and sickened me to the stomach. I love my husband dearly, but working full time, caring for two small children and being his sole carer isn't an easy life to live. I'm sure every carer in the UK would agree with me that we need all the help we can get. Carers are often the unsung heroes that take on the role due to their love of a family member or friend - easing NHS resources.
I have been a carer for the last seven years, and haven't had one bit of help, and what works out to be 50p an hour as I care 24/7 is down right disgusting.
Darren, Bude, UK
I have only been a carer for 11 months and find the amount of bureaucracy terribly frustrating. It can be just as big an emotional drain as caring is. My 77- year-old mother is totally dependant, more help with physio and occupational therapy to help to keep her stimulated would be a God send. Funding to keep physio support for cases like ours is not enough.