The Turnbull government's so-called razor gang is meeting to fine-tune the details of next month's Budget.
Housing affordability is expected to be a focus.
But the Coalition is divided over a rumoured plan to allow young first-home buyers to spend money from their superannuation on a deposit.
Assistant health minister, Nationals MP David Gillespie, is the latest to speak out.
"I tend to think it's a good idea. A lot of the physical barriers to home ownership is getting that initial deposit together. And if one's super fund could, for a period of time, contribute capital into that, and then return it to the super fund later on once you're established, I can't see any problem in it."
And he's not the only one.
Half-a-dozen Coalition MPs and senators have publicly voiced support for the plan, including cabinet minister Matt Canavan and former prime minister Tony Abbott.
Christopher Pyne has criticised his colleagues for speaking out of turn.
"It's a great pity that colleagues run these debates publicly. Whether they attach their name to them, which I think is much more respectable, or do so anonymously. The budget process should be managed behind closed doors and on Budget night it should be revealed to the people."
Mr Pyne launched a vigorous defence of the status quo, saying superannuation should be reserved for retirement, and nothing else.
"Our superannuation system is the envy of the world, and those people who seek to fiddle with it are putting that at risk. And there is no evidence to suggest that if superannuation was able to be used for housing, that would somehow bring house prices down."
The idea of letting young people dip into their retirement savings has been blasted by industry super funds and several leading economists.
They argue the scheme would only add further heat to the property market and drive prices higher.
Existing home owners would benefit, as prospective buyers would turn up to auctions with more capital at their disposal.
Prime Minister Malcolm Turnbull has previously described it as a "thoroughly bad idea".
And Immigration minister Peter Dutton says he's right.
"I think the Prime Minister's made the right call. Now, people have rightly explored options about what you can do around housing affordability. Ruled out negative gearing. And the PM now has dealt with this issue as well so there are other ways that you can provide help but you don't want to fuel prices, you don't want to create a situation that's worse than what we've got at the moment."
The Opposition is pushing its alternative plan to make housing more affordable, by reducing negative gearing tax concessions for property investors.
Labor MP Chris Bowen attacked the apparent division within the government.
"Today the dysfunction and chaos at the heart of the Turnbull Government's economic policy falls to a new low. We have an expenditure review committee meeting of the cabinet meeting today in this building, where ministers are positioning publicly and undermining each other publicly in the lead-up to that meeting."
The details of the government's housing affordability package will be revealed in the Budget on May 9.
