A defence against repossession of the property may be possible on the ground of 'undue influence'.
Mortgage repossession - 'undue influence'
The House of Lords has held that where a lender has reason to believe that the person benefiting from the loan could put a person whose rights are affected by a loan under pressure to give up those rights, then the lender should ensure that this person is given independent advice.  For example, if a wife allows a lender's security to take precedence over her rights of residence in a property and the loan is for the sole benefit of her husband's business this should put the lender on notice of the possibility of undue influence. If the lender does not ensure that independent advice is given then the wife may be able to prevent possession.
This is an unusual and complex defence and borrowers in this situation should be referred to a solicitor for further advice.
Smith v Bank of Scotland 1997 SC (HL) 111; 1997 SLT 1061; 1997 SCLR 765. For a discussion of this case, see 'Standard Securities', by Cusine and Rennie, 2ndedition, Butterworths, 2002, p.9.