With some $65 billion of retail commercial property loans sitting on their books, you can bet your last dollar that the country's big four banks are keeping a very close and anxious watch on the battle royale now being played out between the country's shopping mall owners and major retailers.

The most vocal advocate for scuttling the existing model for retail rents with fixed annual increases is billionaire retailer Solomon Lew. "At the end of the day, the old model of fixed rent payable in advance is not going to work," he declared.