Treasurer Scott Morrison says the federal budget will include some modest tax changes but any broader reform would be taken to the election.
The coalition is under opposition pressure to reveal whether it plans to increase the GST or find other ways to pay for personal and corporate tax cuts and the growing demand for services such as health and education.
Labor leader Bill Shorten has spent the past fortnight touring the country and talking up the threat of the Turnbull government lifting the GST rate from 10 per cent to 15 per cent.
Asked about tax changes on the Seven Network on Friday, Mr Morrison said the May budget would deliver the "next instalment of what we are doing in this area".
"But the issues on broader big tax changes, that will be put to the Australian people at the election," he said.
"As we work through the various issues on tax, whether that's on superannuation or other issues like that, we will have a steady process of bringing the Australian people along with us."
He told ABC radio he was confident state treasurers would cooperate on tax reform to boost the economy.
"One thing I know that can support growth right across the country is a tax system where personal income taxes don't punish people for working more, saving more and investing more," the treasurer said.
Speaking in Alice Springs, Mr Shorten told reporters a rise in the GST would increase the cost of living for families and make small business "the meat in the sandwich".
"Small business will, to a very large extent, have to absorb the price increase and take it out of their own bottom line because they won't be able to pass it on to consumers," he said.
