The Politics Show South has learned that many of those carers who would be eligible for the carers allowance are not claiming it.
And that money which should be spent on social care, because it has not been ring-fenced, is being spent on other things.
Part of the problem is caused by a confusion of pots of money for different things, and the complexities of the form for claiming carers allowance.
Under the government's Carers Strategy, £50m was provided to PCTs across the country to provide respite breaks for carers.
According to the charity the Carers Trust, less than a quarter of that £50m was actually spent by PCTs on carers.
Imelda Raymon: "We were shocked and angry"
NHS West Sussex's share of the £50m pot came to £732,000 for 2009-10.
Of that they have so far spent £62,000 on respite care and say they are currently discussing contracts worth between £200,000 and £300,000.
As Imelda Raymon, chief executive of the Carers Trust, found that situation is quite widespread:
"We wrote to every PCT in England asking them how they were spending the money and how they intended to spend it in the future.
"Many of them came back to us saying, we have no intention of doing anything with this, it is not one of our priorities."
And then there is the money actually paid to carers under the Carers Allowance.
Currently £53.10 a week, to be eligible you have to be looking after someone receiving disability allowance of some kind, and take care of them for 35 hours a week.
Which translates to £1.52 an hour, well below the minimum wage.
Yet even this allowance is not getting through to many of the south's carers.
According to figures obtained by Lib Dem MP Sandra Gidley from the Department of Health, there is a considerable disparity between the number of people eligible for the allowance in a local authority area and those actually receiving it.
The shortfall ranges from over half (53%) in Adur to just under a third (29%) in Slough, but the broad brush picture seems to be that just under half of all those entitled do not get the carers allowance to which they are entitled.
There are some caveats to those figures, in that people may be getting so-called overlapping benefits such as pensions or Job-Seeker's allowance which make them ineligible for the carers allowance.
But even so, there are clearly thousands of carers across the south not getting their full entitlement one way or another.
And with an election imminent, they may well want to know why.
BBC Politics Show (see an additional video on the BBC site)