The social worker is out of order here.
He/she has no way of knowing what your father's care needs might be in 12 months' time. Being realistic, they are more likely to increase rather than decrease, and this means he would still be eligible for NHS funding.
The critical factor is are his needs care needs or nursing/medical needs. If the latter apply now it is likely to apply in a year's time, given that he is elderly.
I think you should go to your local Citizen's Advice bureau or a solicitor about this, so that you have clarity and the worry is not hanging over your head. SSD's do have the right to ask for top-up from a relative or other third party if they the cost of the care exceeds the amount that they are willing to pay, but, as I understand it, they cannot force you to do so and it is a voluntary agreement. However, if no third-party is available to make up the difference, they may insist that the individual goes into a cheaper home that comes within the SSD's limits.
I have copied some useful extracts for you below, but the most important thing to remember is that, sadly, elderly people's conditions tend to deteriorate so it is very unlikely that he will cease to be eligible for NHS funding and the problem should not arise..............................
Top-up fees
The local authority may also agree to pay for a place in a more expensive home if a third party, such as a family member or a charity, agrees to pay the difference. This is often called a top-up fee and in most cases it cannot be paid by the resident.
The amount of the top-up fee is the difference between what the local authority would usually expect to pay (depending on that particular person's care needs) and the extra cost of the care home.
Guidance states that if a top-up is agreed, the local authority remains responsible for all of the care home fees and must contract with the care home to pay these fees in full. The local authority can ask the third party to pay their contribution to the home directly or to themselves. However, the local authority is still responsible for the full cost of the accommodation if the top-up is not paid.
If you agree to pay a top-up fee it is advisable to get a written agreement with the local authority, the home and the resident. The agreement should include information about what will happen with rises in the cost of the care home and what would happen if the fees are not paid.
If top-up fees are not maintained, the local authority may move the person to a home within their budget. However, the person's needs must be met by this new home. To avoid the risk of disruption this could cause, it is important to make sure that you will be able to pay the top-up fees for as long as they are needed, and that you are prepared for possible fee increases.
Guidance states that local authorities should only seek top-up payments where there was a genuine alternative of a cheaper care home (within the local authority's budget) that would have met the person's needs and this home was turned down by the person with dementia or their family. The guidance also states that a local authority cannot ask for a top-up if it has decided to offer someone a place in more expensive accommodation in order to meet their assessed needs.
Will the person's relatives be liable?
When a local authority in England or Wales assesses the amount that the person with dementia should contribute to care, it should consider the income and savings of that individual only. Old rules in England and Wales that allowed local authorities to charge a husband, wife or civil partner were repealed on 6 April 2009.
See also this link for useful sources of advice: http://alzheimers.org.uk/site/scripts/documents_info.php?documentID=125
It is the relevant page of the Alzheimers Society - but the same rules apply whether someone has a dementia illness or not.
