The Housing (Preservation of Right to Buy) Regulations 1989

156.    Liability to repay is a charge on the premises.

(1) The liability that may arise under the covenant imposed by virtue of section 155 is a charge on the dwelling-house, taking effect as if it had been created by deed expressed to be by way of legal mortgage.

(2) The charge has priority immediately after any legal charge securing an amount–

(a) advanced to the qualifying person for the purpose of enabling him to exercise the right to buy, or

(b) further advanced to him by the person who made that advance.

(3) A charge taking effect by virtue of this section is a land charge for the purposes of section 59 of the Land Registration Act 1925 notwithstanding subsection (5) of that section (exclusion of mortgages), and subsection (2) of that section applies accordingly with respect to its protection and realisation.

(3A) The covenant imposed by virtue of section 155 (covenant for repayment of discount) does not, by virtue of its binding successors in title of the qualifying person, bind a person exercising rights under a charge having priority over the charge taking effect by virtue of this section, or a person deriving title under him; and a provision of the conveyance or grant, or of a collateral agreement, is void in so far as it purports to authorise a forfeiture, or to impose a penalty or disability, in the event of any such person failing to comply with that covenant.