In the absence of a contract to the contrary, the mortgagee has, at any time after the mortgage-money has become ³[due] to him, and before a decree has been made for the redemption of the mortgaged property, or the mortgage-money has been paid or deposited as hereinafter provided, a right to obtain from the Court ⁴[a decree] that the mortgagor shall be absolutely debarred of his right to redeem the property, or ⁴[a decree] that the property be sold. A suit to obtain ⁴[a decree] that a mortgagor shall be absolutely debarred of his right to redeem the mortgaged property is called a suit for foreclosure. Nothing in this section shall be deemed—

¹[(a) to authorise any mortgagee other than a mortgagee by conditional sale or a mortgagee under an anomalous mortgage by the terms of which he is entitled to foreclose, to institute a suit for foreclosure, or an usufructuary mortgagee as such or a mortgagee by conditional sale as such to institute a suit for sale; or]

(b) to authorise a mortgagor who holds the mortgagee's rights as his trustee or legal representative, and who may sue for a sale of the property, to institute a suit for foreclosure; or

(c) to authorise the mortgagee of a railway, canal or other work in the maintenance of which the public are interested, to institute a suit for foreclosure or sale; or

(d) to authorise a person interested in part only of the mortgage-money to-institute a suit relating only to a corresponding part of the mortgaged property, unless the mortgagees have, with the consent of the mortgagor, severed their interests under the mortgage.