Bill Shorten will look at the tax reform "too-hard basket" if Labor wins government, but a colleague says this doesn't mean a GST hike is on the cards.
The opposition leader will use a speech to an conference in Melbourne on Friday to pledge to tackle inequality if he becomes prime minister.
He call for a reconsideration of tax reforms that have previously been dismissed as politically difficult.
"It's time to go to the too-hard basket in tax reform and re-examine the issues," he will say.
"Australians are ready for an authentic debate about whether our tax system accurately reflects the values of our country."
Senior Labor MP Anthony Albanese denied this implied Labor could hike the GST.
"No. What Bill Shorten will be talking about today is the issue of inequality and the fact that inequality is at a 75 year high," he told the Nine Network.
Labor wants a debate about "fairness" and has already put possible changes to capital gains tax and negative gearing on the table, he said.
"People said that was too hard as well but we need to address it in terms of housing affordability," the frontbencher added.
In his speech, Mr Shorten will blame inequality for fracturing the nation, driving Australians away from the major political parties towards minor parties like One Nation - "down the low road of blaming minorities and promising to turn back the clock".
He will insists the coalition government is too out of touch to recognise the struggle of average Australians and flag tax reform as the way forward.
"I don't think it's good enough to hide behind some sort of philosophical objection to government intervention," Mr Shorten will say.
"I didn't run for parliament just to shrug my shoulders and say: `Oh, the invisible hand will help you, the market will decide'.
Treasurer Scott Morrison on Thursday conceded not all Australians had benefited from the nation's world record 26 years of continuos economic growth.
"It's our job to make sure that we spread that growth as far and wide as possible," he said.