When will a mortgagee succeed in a claim against the mortgagor?

The dissenting judgment in Forster v. Ivey was given by MacLennan J.A. who was of the opinion that the appellant should succeed on two principles. First, because where a mortgagee has put it out of his power to restore the mortgaged property to the mortgagor on the payment of the debt, he will be restrained by the court of equity from suing on the covenant. At p. 493 he said: The mortgagee has, therefore, by his agreement with the present owner made his mortgage unredeemable by the mortgagor according to its terms, and the effect of that must be to discharge the mortgagor from liability altogether.

MacLennan J.A. cites numerous authorities for this proposition and it should be given considerable weight. He cited the case of Gowland v. Garbutt (1867), 13 Gr. 578, where a mortgagee had put it out of his power to recover a part of the mortgaged property but had afterwards obtained it back. It was held by Mowat V.-C. [at p. 583] that: ... mortgaged property cannot be redeemable and irredeemable, from time to time, and the mortgage debt discharged and revived, at the mere pleasure of the mortgagee and those claiming under him. The right to foreclose once gone is, I apprehend, gone forever...