James and Rebecca remain liable for the shortfall under the mortgage deed and ZenithBank can pursue them under the deed for the debt. Even in the absence of an express personal repayment covenant in the mortgage deed, common law implies an obligation to repay all capital and interest into the mortgage deed. Since ZenithBank has not foreclosed on its mortgage but merely exercised its power of sale, the mortgage deed continues to have effect. Therefore, ZenithBank can pursue James and Rebecca for the £20,000 shortfall. Key Point: In the absence of an express repayment covenant, common law implies an obligation to repay all capital and interest into the mortgage deed. This allows the mortgagee to pursue the mortgagor for any shortfall following the exercise of the power of sale, provided the mortgage has not been foreclosed.