Ian makes some interesting points - from my experience HMRC simply want to see that you are putting best feet forward, and if your mortgage and secured loan repayments are excessive, perhaps they have a point that you ought to consider selling and moving into cheaper rented accomodation.
They are entitled to their opinion, and so are you to yours. Once they have a bee in their bonnet about something, they rarely budge, and if you have equity in the property (which may be unlikely given your secondary lending), then bankruptcy might also be an option - although this could affect your husband's ability to trade.
You also have the option of offering a debt management programme, but again HMRC can be awkward about accepting ongoing repayments, and may be likely to petition for your husband's bankruptcy as an alternative. Best to seek the advice of your own IP who has more detailed knowledge of your case than can be shared properly on the forum.
Regards, Melanie Giles, Insolvency Practitioner