The federal Treasurer, Peter Costello, is defending his budget against Opposition accusations that its big-spending will force interest rates higher.
Mr Costello last night unveiled across-the-board tax relief in his 11th federal budget, offering more help for families among other measures.
The opposition has challenged Mr Costello to guarantee that interest rates won't rise as a result of the government's spending spree.
Mr Costello has told the parliament rates will never rise to the levels seen under the most recent Labor government.
"Mr Speaker, the evidence is there - this is the government which has so run economic policy as to keep interest rates low.
"We will continue to manage the Australian economy as to keep interest rates low and they will be substantially lower than the Australian Labor Party's 12.75 per cent."
Last week, the Reserve Bank lifted the official interest rate by a quarter of a percentage point to 5.75 per cent, its first move since March last year.