Amid mounting speculation his government will bring forward income tax cuts that have already been legislated, the prime minister said he always jumped at an opportunity to give people a break.

"My record is lowering taxes for Australians," he told reporters in Melbourne on Monday.

"We currently have $144 billion worth of tax relief for all working Australians in this country, and wherever I get the opportunity to give Australians further tax relief, I never miss the opportunity."

Treasurer Josh Frydenberg at the weekend did not rule out further tax relief, saying only that the budget would frame the coalition's election pitch.

"The next election will be about what kind of nation Australians want over the next decade," he told The Australian.

"On our side it is about balancing the books, growing the economy with more jobs and lower taxes."

Senior Liberal Arthur Sinodinos on Sunday said tax cuts could help those with lower incomes until wage growth picks up.

Proposals from the ACTU and others to lift the minimum wage would deliver a pre-tax increase but a similar effect could happen through a "proper tax cut for low and middle-income earners", he told the ABC's Insiders.

The government passed a personal tax cut package through parliament last June, with the first stage kicking in for the current financial year.

Further reductions are due in 2022 and 2024, leading to a single person on $30,000 ultimately getting a tax cut of $200 a year, while someone on an average wage of around $85,000 would get $540 and a $200,000-a-year salary earner would get $7225.

Labor has opposed the higher-income tax reductions and says it will give cuts of $350 to people earning $25,000 and up to $928 for people on $90,000 a year.

"All I know is that we are offering bigger, better, fairer tax cuts," Opposition Leader Bill Shorten told reporters in Melbourne.

"If the government does more we'll have a look at it, if the nation can afford it."

The budget will be handed down on April 2 and an election is expected in mid-May.

Australian Associated Press