Allan makes car parts but the closure of the car manufacturing industry in Adelaide has badly affected his business and Allan is finding it difficult to make rental payments for the factory that he leases from Ben. Allan was looking to other markets into which he could sell car parts.

In February 2021 he told Ben that he was having difficulties paying rent and said "You already have factories you cannot lease and if you do not reduce my rent you may have one more. Would you consider reducing my rent by half? Ben agreed to do so until Allan's business improved.

One year later, Allan's business had not improved. By this time, Ben's business was also experiencing financial difficulties and so he demanded that Allan pay full rent from March 2022, as well as arrears, explaining that he needed all the money to retain ownership of the factory premises. Allan has refused Ben's demands.

Does Promissory Estoppel apply in this scenario?If so, Why?