What to make of One Nation's latest policy. The minor party has suggested putting Australians into 30-year fixed-rate home loans at 5%, sold over the counter at Australia Post, with the tab picked up by scrapping the Albanese government's $11.5 billion Housing Australia Future Fund. It's a neat pitch on paper – a rate comfortably below the 6%-plus average on new owner-occupier loans, unlocked with just a 5% deposit that could come from superannuation or a first-home buyer grant.

Richard Holden, an economics professor at the University of New South Wales (UNSW), told the Australian Financial Review the real funding bill could balloon to 10 to 50 times the advertised $11.5 billion once borrowers inevitably stampede toward the cheaper government rate. Challenger chief economist Jonathan Kearns has raised a related concern – who wears the losses if house prices fall and defaults follow? Even One Nation can't quite agree with itself: Treasury spokesman Barnaby Joyce has downgraded the plan to "a discussion piece," while leader Pauline Hanson insists the costs are already capped and budgeted. The Broking industry asked brokers, lenders and aggregators what they actually make of importing a very American idea into a very Australian market – and the consensus is that the two systems don't translate quite as neatly as a 30-year fixed rate might suggest.

An online poll found mixed support for such a scheme, with 44% saying they would support 30-year fixed mortgages and 56% saying they wouldn't. In Australia, break costs apply whenever a borrower exits, refinances, or switches a fixed-rate loan before the term ends, and they're calculated on the difference between the wholesale rate at the time of fixing and the wholesale rate at the time of exit, multiplied by the loan balance and the remaining term. Because Australian lenders fund fixed-rate loans through wholesale markets rather than a deep securitised secondary market, they pass that funding-cost mismatch directly onto the borrower.

Tony MacRae chief commercial officer at Bluestone, agrees that there are fundamental differences between the US and Australian markets. While there may be consumer appeal for 30-year fixed loans, Australia's funding model is very different to the US, where long-term fixed rates are supported by a deep secondary mortgage market, said MacRae. It's not something that can be easily replicated here, and there are significant funding and pricing challenges lenders would need to investigate before participating.