You will have to disclose your defence at some stage and it is far better (in my opinion anyway) to do this at an early stage which may well prevent court proceedings being issued at which you are going to have to disclose your defence anyway!(posted 6985 days ago)Royal Sun can add interest onto the shortfall - under the statute of limitations act though, interest can only be claimed for six years, and the shortfall for 12 years, but there is an agreement that CML lenders will only pursue for shortfalls for 6 years under the voluntary code.
You do not give enough information (i.e. when defaulted, amount of shortfall, current position, whether debt acknowledged or not) to give a concise answer, but you may in certain circumstances, be better off by making an offer instead of going to court where it will ultimately cost you more and may lead to loss of current home or claims on wages or goods.