My client is likely to incur a NDD on his mortgage interest for caring for his sick mother who has recently moved in. There will be no NDD on the CTB as she will be on IS but, so far as I can see, there will be on his housing costs paid by the DWP.

If he was in rented accommodation, there would be very little difficulty in this particular case in obtaining a DHP to make up the shortfall. The commentary to Reg 2 Discretionary Financial Assistance regs in Findlay suggests that the LA may have power to award a DHP for Housing Costs where CTB is in payment. A quick conversation with the local HB section has confirmed that they will not entertain the idea.

Has anyone had any success in obtaining a DHP for mortgage interest in these circumstances or has it been considered by the Courts at all?

The DWP guidance to LA's states very clearly that the reference to "Housing Costs" in Reg 2 means council tax and rent - nothing else. I am not saying this is correct in law but it does presumably reflect the policy intention of the DHP scheme. It would also explain why the LA will "not entertain the idea". I think it would be news to most LA's that they could consider DHP's for other housing costs, although I agree that the wording of Reg 2 suggests they could. I do not know if this has been considered by the courts.

I guess that it would be fruitless pursuing a claim through JR then, but I am perplexed as to why they didn't explicitly exclude mortgage interest payments from the scheme when they could have done so very easily. Why not just refer to reg 8 HB regs rather than the rather convoluted exclusions in reg 3?