Wealthy parents should "shell out" and buy their children houses, Mr Turnbull said in off-the-cuff remarks on Wednesday, comments which have been seized on by the opposition.

The comments, made to one of the ABC's star radio hosts, Melbourne presenter Jon Faine, are reminiscent of former Liberal Treasurer Joe Hockey's infamous gaffe, when he said people trying to afford a good home should get a good job.

Mr Hockey was dumped as treasurer after a series of similar gaffes, including his observation that poor people don't drive cars, as he was seen as out of touch and insensitive.

Mr Turnbull made his comments during a media interview to sell his first budget when he was asked about negative gearing, which Labor has pledged to curb, but the government says it will not change.

"[Negative gearing's] created conflict with effectively the kids of your and my generation who can't get into the market and they're saying 'for goodness sake, you baby boomers, you just want everything and you're locking us out,' " Mr Faine said.

"Are your kids locked out of the housing market?" Mr Turnbull responded.

"Yes," said Mr Faine.

"Well you should shell out for them. You should support them, a wealthy man like you," Mr Turnbull told the radio host.

"That's what they say," Mr Faine responded, laughing.

"Yeah exactly, see you've got the solution in your own hands… you can provide a bit of inter-generational equity in the Faine family," Mr Turnbull said.

Opposition Leader Bill Shorten went on the attack in question time.

"Is that really the Prime Minister's advice for young Australians struggling to buy their first home? Have rich parents?"

Mr Shorten also raised Mr Turnbull's recent media event with a family in Sydney which backfired, after the parents said they had purchased an investment property for their one-year-old child.

"Can the Prime Minister confirm that in the past two weeks his advice to young Australians struggling to buy their first home was to have rich parents or to have parents who buy you a home when you turn one."

"Prime Minister, just how out of touch are you?" Mr Shorten said.

Mr Turnbull accused Labor of waging class-warfare.

"They are sneering at the hardworking Australians who seek to make something for their children. And they dare to talk to us about being out of touch! This is a war - a political war - they want to commence against aspiration, against ambition, against enterprise," he said.

In the Senate, Labor's Doug Cameron asked if Mr Turnbull had helped buy his daughter, a teacher, a subpenthouse in a high-end part of Sydney's eastern suburbs.

"I know that history teachers in New South Wales, after a number of years of experience, are on about $65,000 a year. But Miss Daisy Turnbull Brown is able to buy a subpenthouse, with knockout views of the harbour and city skyline, in 2008 - she was then aged 23 - for the pricey sum of $2.7 million," he said.

"There was a bit of intergenerational equity getting moved in that one, because there is no doubt that Ms Turnbull Brown had no chance, under her own steam, of getting such a penthouse with stunning views.

"Get in touch with the real-life people of this country and stop the nonsense that negative gearing promotes," Senator Cameron told the prime minister.

Nationals Senator John Williams urged Senator Cameron to fess up to owning a waterfront flat on the Kingston foreshore – one of Canberra's most expensive suburbs.

Mr Turnbull, a multi-millionaire who last week admitted to buying his wife a Cartier watch, valued at tens of thousands of dollars, has already been the target of numerous other Labor attacks aimed at his wealth.

In one of his first interviews he was asked about how he could expect to relate to everyday Australians given his net worth, conservatively estimated to be about $200 million.

The member for Wentworth reprised an anecdote from his time as a partner at investment banking firm Goldman Sachs in New York.

"The chief executive of the firm gave a sort of pep talk to the partners and he said, you know, 'We're doing well. We're making lots of money 'cause we work hard and we deserve it.' And I said to him afterwards, just quietly, I said, 'You know, there are taxi drivers in this city that work much longer hours than anyone does here and they don't earn very much at all,' " he said.

He nominated the ability to empathise instead as the key factor.

"Emotional intelligence is probably the most important asset for - certainly for anyone in my line of work," he said.

Early on in his prime ministership, Labor attacked Mr Turnbull for holding investments registered in the Cayman Islands.

Many leading political commentators condemned the tactic.