Australia has become "a nation that can no longer house its own children", Labor's Chris Bowen has warned, with soaring home prices cutting young people out of the market and a generation facing a crisis in affordability.

And Mr Bowen says the growing wealth of the super-rich one per cent - and the relative decline in middle-class incomes - has caused the surging popularity of nativist parties like the Nick Xenophon Team and Pauline Hanson's One Nation, Donald Trump in the United States and the success of the "Brexit" campaign.

"We can't expect middle-income earners to support globalisation and outward-looking policies when they can see scant evidence that it is working primarily for them," he will say.

In a major speech to the McKell Institute in Melbourne on Thursday, obtained by Fairfax Media, the opposition treasury spokesman will set out Labor's philosophical approach in the next term to economic management, inclusive growth and, crucially, the case for winding back negative gearing tax breaks.

The speech, The Case for the Middle Class, is designed to position Labor squarely in the political middle ground and establish the opposition as the successors to the reforming Hawke-Keating government.

Mr Bowen will argue that, in 2016, "Menzies' forgotten people [ie, the middle class] are more forgotten than ever before" - a pointed reference to falling national income on a per-person basis and largely stagnant real incomes for the last decade.

He will also raise the prospect of a US-style class of "working poor" emerging in Australia, warning the minimum wage has fallen from 63 per cent of the median national income to 53 per cent in the last 20 years.

This fall, he will argue, underscores the need for a strong minimum wage and for penalty rates to be protected, and in part has happened because of the decline in union membership in Australia.

But it is the declining rates of home ownership among younger Australians, which for many is now just a "pipedream", that most concerns Labor's chief economic spokesman.

"Overall home ownership in Australia is at a 60-year low. In 1982, 62 per cent of people aged 25-34 owned their own home. By 2012, this had collapsed down to just 42 per cent," he will say.

"Over the last 25 years, young people have gone from having to pay just five times, to now having to pay up to 15 times their annual income to purchase a new home."

"The inability of young people, in particular, to buy a home to accommodate them has reached, I say calmly and soberly, crisis levels. We are a nation that can no longer house its own children."

The speech represents the most thorough-going explanation for Labor's bold negative gearing and capital gains tax policies, which were released earlier this year as the July election loomed,.

Those policies were roundly criticised by Prime Minister Malcolm Turnbull, Treasurer Scott Morrison and the Coalition, who warned they would smash house prices across the country.

But a defiant Mr Bowen says: "This is exactly the sort of pro-middle class policy that shows people who feel forgotten that, actually, they are front of mind" and that it is simply not good enough for "governments to shrug their shoulders" and let the market rip.

The "moral case" for the middle class, he will argue, is that it is a key driver of economic growth - but those middle-income earners must benefit from increasingly open markets, freer trade and greater immigration, rather than falling further behind.

"People whose incomes have been stagnating provided the bulwark of the "leave" vote in the UK. And . . . who are providing the support for the isolationist approach being put in the current US presidential election," he will say.

Similarly, the July 2 poll saw large swings . . . in areas where the economic transition is not going well and people felt left behind. "In South Australia and Queensland, some of that swing went to third parties presenting nativist, populist solutions to the middle-income squeeze".

"Hawke and Keating understood that while undertaking the opening up of the economy, this was only one part of the story. As they floated the dollar, deregulated foreign involvement in our financial system and brought down tariffs, they instituted Medicare, provided the social wage and lifted school retention rates. They understood that these were vital re-assurances."

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