National Australia Bank has implicitly accused Commonwealth Bank of Australia and BankWest of losing their lending appetite and launched a campaign to poach property borrowers disaffected by their indefinite suspension of some lending.
NAB is also telling mortgage brokers and potential borrowers that it is still "accepting all new business, refinances and other home loan applications" in direct defiance of CBA's clampdown.
"You may be aware there's some movement in the market at the moment around lending appetite for certain customer segments," Steve Kane, NAB's general manager of distribution has told mortgage brokers.
"I'd like to confirm that NAB remains committed to the broker channel and that NAB remains open for business for both owner occupied and investor borrowers."
Other lenders are likely to follow NAB's lead with special offers and bigger discounts in a bid to boost interest margins in booming investment markets.
The letter informs brokers that details of its new lending push is for their own information and not to be told to clients.
It follows CBA, the nation's biggest lender, and its Perth-based BankWest divisions decision to suspend new finance applications for some investment home loans.
Neither bank has provided a reason for the decision but refer to 'regulatory obligations', which is widely considered to be a signal it is pulling back on lending because of concerns regarding breaches of the Australian Prudential Regulation Authority's 10 per cent lending speed limit, which is calculated on a monthly rolling basis.
CBA has never exceeded the limit.
Annualising the monthly net movements in investment loans during December shows CBA was growing at 10.3 per cent, according to analysis by Digital Financial Analytics. It is a raw number that includes a lot of assumptions but indicates CBA and BankWest's regulatory headroom was shrinking.
CBA also announced the reduction of discounts on some loan packages and has abolished a $1250 refinance rebate for some other loans.
New investment loans account for about 35 per cent of CBA and BankWest's combined lending book and 33 per cent of new mortgage lending. The banks do not identify how many investment loans are transferred from other lenders, which is the target of this week's ban announcement.
Mr Kane said "we continue to support all of your customers with our lending policies".
NAB has announced an annual fee waiver worth $395 on NAB Choice Package and $1500 Home Loan cash back offer who take out a NAB home loan and 'banking bundle'.
Other banks, including SunCorp, are also attempting to build property investor market share by offering discounts of more than 100 basis points to new borrowers.
Analysts suspect lenders attracting new business from CBA could also rapidly approach the 10 per cent limit.
In a follow-up statement, NAB said it sent the letter to brokers after "receiving a number of queries from aggregators and brokers as to whether NAB's home lending policies had changed".
"I wanted to confirm to all of our brokers that our policies have not changed, and that NAB is accepting all new business, refinances, and other home loan applications in line with our policies," Mr Kane said.
