There is a personal �3,000 (annual) tax free gift allowance � which can be carried forward for one year, if not used. Therefore if your father has not given any gifts over the previous financial (tax) year (2007-2008), he can give �6,000 in total this year (2008-2009). Since the tax year is coming to an end, in early April he will be able to give another �3,000 (2009-2010), making a grand total of �9,000.
Although your father might be using these gifts to reduce his payments for care � should he at some later date want the �gifts� returned, he would have no legal claim over the money gifted. However those receiving the gifts, could gift the money back to him at some later date, under their tax free gift allowance.