Budget saved triple-A rating: Turnbull

Malcolm Turnbull believes without revenue measures in his government's second budget, such as the bank levy, Australia would have lost its triple-A credit rating.

All three major credit rating agencies have confirmed Australia's top-tier rating since the May 9 budget, although one - Standard & Poor's - has kept the rating on a negative outlook, leaving open the risk of a downgrade in the next couple of years.

"If we had not raised this additional revenue measures, I don't think many people imagine we would have been able to retain that triple-A rating which is so important for all Australians, but in particular, it is very important for the banks," the prime minister told reporters in Canberra on Monday.