Treasurer Scott Morrison has brushed aside a new opinion poll that shows voters rejecting a hike in the GST, saying boat turnbacks were once far less popular.
What was more important was doing what was right for the Australian economy, he insisted.
"I'm no stranger to causes that don't enjoy popular support," the former immigration minister told reporters in Canberra on Monday.
"For five years I campaigned heavily on what were very unpopular measures."
More than half of voters reject increasing the GST rate even with compensation and tax cuts, the latest Newspoll shows.
Opposition Leader Bill Shorten said it was clear a 15 per cent GST on everything was "wrong, wrong, wrong".
"Today we see more and more evidence that Australians aren't buying the snake oil of Mr Turnbull and his Liberals," he told reporters in Melbourne.
But Australian Chamber of Commerce and Industry chief executive Kate Carnell was amazed that only 54 per cent rejected the idea of a GST increase.
"If you ask most Australians if they want any tax increase, they usually say no," she told reporters in Canberra.
The poll came as NSW Premier Mike Baird launched a new offensive arguing the consumption tax should be raised to 15 per cent by July next year to pay for health and education spending.
He believes $32 billion a year could be raised in 2017/18 to deliver the states $7 billion to cover funding gaps.
His "modified consensus plan" would include compensation for low-income families and reductions to company and income taxes.
"I think that is a good deal," Mr Baird said in a video message posted on Twitter.
But NSW Opposition Leader Luke Foley said it would punish households to prop up big business and corporations.
"Labor won't have a bar of it," he told reporters in Sydney.
Queensland Premier Annastacia Palaszczuk agreed and said it was time the federal government put its tax plan on the table.
"We're going to be facing a federal election this year. Stop dealing in hypotheticals," she told reporters.
However, South Australian Premier Jay Weatherill sees it differently, supporting a GST hike if used for health and education spending, and deepening a rift with federal Labor.
Senior Labor senator Stephen Conroy warned the premier he would be "utterly" rejected if he took an increase to a state election.
Finance Minister Mathias Cormann said the commonwealth was talking to all the states and territories about tax reform ahead of a COAG meeting in late March.
The government was determined to create a tax system that was as "growth-friendly as possible" but had yet to reach a landing point on an overall package.