A spokesman for Mr Abbott said: "It is simply not true that the government only started looking at tax issues last September."

Mr Morrison later tweeted that he wasn't criticising his predecessors. "My comments on tax issues put back on the table by the PM were not a criticism of Mr Abbott or Mr Hockey but a statement of chronology," he wrote.

The Coalition under Mr Abbott came to power in 2013 promising a tax "white paper" that would set out the government's tax strategy. Next month marks a year since a discussion paper designed to promote debate on tax was released.

A tax white paper unit was established and hundreds of organisations made detailed submissions.

Sources working behind the scenes said they were hamstrung by Mr Abbott's decision to rule out any changes to superannuation, negative gearing or dividend imputation. And it wasn't until August of last year that the states raised the prospect of increasing the GST.

This week senior government ministers declared a GST increase was no longer being considered as an option for funding income tax cuts and other changes to the tax system.

Bracket creep

An increase in the GST rate to 15 per cent would have given the government $30 billion to spend. It is now looking at more modest means of raising extra revenue.


Mr Morrison is preoccupied with bracket creep – where inflation leads to people paying more tax – and has indicated any tax cuts will be directed at preventing average income earners moving into the second top tax bracket.

Pressed by 3AW's Neil Mitchell for a sweeping economic vision for the country, Mr Morrison said there was no silver bullet.

"What you're looking for is some big hit that solves all our problems in one go and the reality is that doesn't exist," he said.

"What the country needs is a government that will be sober and responsible in what are very difficult economics times. To do the hard work of keeping the budget under control over time, to ensure that new spending doesn't overwhelm the budget, that the savings continue and that we don't go down the path of tax and spend."