Govt will seek mandate before tax change

The Turnbull government has yet to decide whether it will pursue a hike in the GST but any change will be put to voters at the next election, a senior Liberal insists.

Finance Minister Mathias Cormann says the government is focused on making the tax system more growth-friendly in order to steer the economy away from resource driven growth.

The government had not made a decision about changes to the tax system or the GST but would get a mandate from voters at this year's federal election, Senator Cormann told ABC radio on Thursday.

South Australian Premier Jay Weatherill appeared to take a swipe at Opposition Leader Bill Shorten's opposition to changing the GST.

There was a "massive and undeniable revenue problem" threatening school and hospital services, as well as the federal budget.

"Both major parties at a national level must front up to the fact that we need to find additional revenue," Mr Weatherill told The Australian.

Labor backbencher Nick Champion told Sky News he was "stunned" any Labor premier would support a change to the GST.

Assistant Minister to the Prime Minister Alan Tudge said Mr Weatherill showed "what a small person" Mr Shorten was.

Mr Shorten said he didn't blame state politicians, who were facing a "fiscal cliff" because of the federal government's cuts to schools and hospitals.

"I understand that they've effectively been taken hostage by the massive cuts that the Abbott-Turnbull governments are imposing on schools and hospitals," he told reporters in Darwin.

A 15 per cent GST would not only mean higher living costs but would kill consumer confidence and force small businesses to lay off workers.

"It's a rotten idea and it should be put in the dust bin of history and that's where Labor is going to put it."