Even before it is delivered on Tuesday, the budget's looming broken promises are bringing a political backlash.
Anthony Albanese pledged at the election not to touch negative gearing or capital gains tax - the budget is set to alter both.
Treasurer Jim Chalmers is not unaware of the political reaction but argues "what matters most at the end of the day is taking the right decisions for the right reasons".
"Without coming at the specifics of these policy issues that have been speculated about, if we come to a different view we'll front up and explain why," Chalmers tells The Conversation in a pre-budget interview.
His point about "coming to a different view" will be contested. It is more credible that Chalmers and others in Labor wanted to change these taxes all along. But the experiences of former leader Bill Shorten had shown the risks of proposing such changes before an election, and how far Albanese would go was always a question mark.
Chalmers said there were good reasons in the election campaign to focus on supply. "I think there has been a welcome focus now on some of the intergenerational issues in our housing market and in our tax system.
"And I genuinely believe that if you come to a different view on a key issue that the onus is on you to explain why."
Chalmers casts this budget as "the balance point" between a year of delivering previous commitments and the coming year "of ambitious reform".
"The commitments we took to the people in 2025 [on housing] were focused largely on supply as well as 5% deposits [to help first home buyers].
"We've been working very hard to deliver on those commitments and like any government [we] are always looking for where we can make a meaningful difference.
"This budget is about making a difference and making difficult decisions, not just marking time.
"And I think these sets of issues, these really quite defining anxieties about how hard it is to get a toehold in the housing market - I think there has developed a sense of urgency to deal with them."
Chalmers is anxious to reject the claim that by stressing intergenerational equity the government is indulging in intergenerational warfare.
"On the specific question around these intergenerational concerns, we do not intend for one second to blame one part of the Australian community for the difficulties being faced by another part of the Australian community.
"We have no intention of setting one group of Australians against another group of Australians.
"We don't blame older people for making the most of the tax arrangements, including those put in place by [prime minister John] Howard and [treasurer Peter] Costello a quarter of a century ago.
"We want more people to be able to access the housing market […] we see that as an important way to get more people having a toehold in the economy more broadly."
One change the budget won't make is to impose a new tax on gas exports.
Chalmers said he understood there were "really strong views" in favour of this and he understood the arguments.
"It was one of the reasons why I reformed the PRRT [Petroleum Resource Rent Tax] in the first term.
"I know that people would like us to go further than that, but from the government's point of view and for the foreseeable future there are good reasons to prioritise these two way supply arrangements in the region on fuel. Getting the gas reservation scheme in place, which is about energy security, industrial capacity and price. Those are more important things to do for the foreseeable future."
This week the government announced that under its gas reservation scheme, producers of liquefied natural gas on the east coast will be required from July 2027 to put aside 20% of their gas exports for the Australian market.
When it is put to Chalmers that he doesn't seem to be ruling out forever going further on gas tax, he said it was one of the issues in the public debate but "it's not something that I'm anticipating".
As well as tax changes, the budget will contain a package aimed at improving productivity. These include measures to reduce red tape, remove barriers to trade, make it easier to engage with government, accelerate approvals and simplify building regulations.
They also include making it quicker to recognise the skills of migrant tradespeople, and reforming the permanent migration points test for skilled visas to select better educated, higher-skilled and younger migrants.
This is Chalmers' fifth budget. Costello delivered a dozen, as he waited, in vain, for Howard to retire. With Labor set to win perhaps another couple of terms, is Chalmers prepared to contemplate Costello's milestone?
"I find it hard to imagine that anyone would do a dozen."
"That's amazing because I know how much these budgets take out of people."
Michelle Grattan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
