Is Pontus entitled to a remedy under s 18 ACL?

Pontus leased a shop from Westminster Properties, and he also lived on the premises. When the time came for the lease to be renewed, Westminster Properties wanted to include a new clause in the tenancy agreement that the shop could only be used for business premises. Pontus made it clear that he wished to continue to live above the shop and that he would not sign the new lease. Westminster Properties stated that if Pontus signed the new lease, with the new term, there would be no objection to him continuing to live on the premises. Pontus signed for a three-year period. If Pontus assumed that he would not have been able to continue to live above the shop, he would not have signed the new lease and would have gone to live at new premises that were available at the time and where he could have lived in the shop.

After six months, Westminster Properties received an offer from a developer who wished to buy the premises, but on the condition that they were empty. Accordingly, Westminster Properties sought forfeiture of the lease on the basis that Pontus was in breach of its terms by residing on the premises.