The extent to which your income is relevant depends on how intertwined your expenditures are.(posted 9096 days ago)I would argue that if your husband has responsibility for outgoings as a result of your relationship then there is no moral reason that those outgoings should instead by paid by you as a result of something that happened to your husband in the past. You would, in effect, be subsidising the Abbey National's thirst for money through no fault of your own.
You can, however, be sure that the Abbey national does not see things this way and you might therefore choose not to draw attention to your part in your husband's financial affairs.
As I explain in other parts of this site, you should not complete and return income and expenditure forms. You should instead serve a subject access rights on the lender and review the results before you do anything else.
Lee