The federal government's plan for a bank levy is under fire with questions being asked why worldwide banking giants that operate in Australia aren't subject to the controversial six basis point levy on liabilities.

"New spending has been fully offset and average real growth in payments has been restricted to less than two per cent over the forward estimates", Mr Morrison said.

"Having exhausted every opportunity to secure savings from our 2014-15 and 2015-16 Budgets, we have made a decision to reset the Budget by reversing these measures at a cost of $13 billion".

Australia was set to unveil a "practical" budget Tuesday focused on infrastructure spending and housing affordability with the government "listening" to frustrated voters.

The government says it's still on track to return to surplus in 2020-21, and is gambling S&P won't penalise its splurge on productivity-enhancing infrastructure.

"We commend [Treasurer] Scott Morrison for jumping on the Productivity Commission's recommendation to introduce an open data regime for banks in Australia", said RateSetter Australia chief executive Daniel Foggo.

"This new tax is not a well thought out policy response to a public interest issue, it is a political tax grab to cover a budget black hole".

Mr Morrison described the 0.06 per cent levy as "modest" as he confirmed the impost would be permanent, and not just a temporary budget fix measure.

'I'm uneasy about it, and I understand banks do pay company tax. but the arguments against the mining tax applied by Wayne Swan can be applied here with equal force, ' the former prime minister told a post-Budget forum in Melbourne on Wednesday.

First home buyers will be able to save for a deposit by salary sacrificing into their superannuation account over and above their compulsory superannuation contribution from July 1.

Initially, Mr Turnbull - in answer to a question from Opposition Leader Bill Shorten - said the total cost of the 10-year plan was $26 billion.

This Budget also delivers important increased support for veterans mental health, protections for children within the family justice system, victims of domestic violence, closing the gap for Indigenous Australians and creating the National Redress Scheme for victims of institutional child sexual abuse.

We will also invest $1.4 billion in ground-breaking health research over the next four years, including $65.9 million this year, to help research into children's cancer. And the federal budget confirms that the cost of a tertiary education is only going to get more expensive, with student fees rising 7.5 per cent by 2021.

"If [Labor] seriously think Australian business can compete with a tax rate of 30 per cent when other comparable countries are at 20 or 18 per cent or in terms of the United States, heading to 15 per cent, they are dreaming", Mr Turnbull said.

Growth to slow this year, but to pick up to 3% annual over the next two years, debt to continue rising and worryingly, no improvement in wages for much of the next four years.

The budget was the first since the government was re-elected on a tiny majority a year ago.

The Government has also heard the anger over housing prices.