518. Loss of right to sue by cause of action estoppel.

518.     Loss of right to sue by cause of action estoppel.

It may be an abuse of process for a party in subsequent proceedings to raise a ground of claim or defence which could have been but was not raised in earlier proceedings1. Therefore, a mortgagee who obtains judgment for possession and for the sums expressed to be due under the mortgage cannot bring a subsequent claim for sums due under a guarantee which were also secured by the mortgage2. A mortgagee is not, however, necessarily required to enforce all his rights in one action: