A Turnbull government backbencher has joined calls for major tax reform with the country facing an ageing population.
Liberal MP Tim Wilson believes there needs to be "dramatic reform" to build an economy for the 21st century rather than relying on a tax system anchored in the 1950s.
"The costs associated with an ageing population are quite dramatic and the number of people we are taxing to support it is narrowing," Mr Wilson told Sky News on Monday
"That's not sustainable, so we have to look at broad-based tax reform."
He said the government's planned reduction to company tax is part of making the economy competitive, but reform needs to go much further.
Nearly three-quarters of the federal government's tax base is generated from income tax, which means working age people are going to be continually hit hard.
He said every tax needs to be on the table for discussion, including the GST.
"Not just the tax but who's paying it and critically at what stage of life," he said.
Last month independent senator Tim Storer held off supporting the coalition's business tax cut until the government agrees to broad tax reform.
The International Monetary Fund and the Organisation for Economic Cooperation and Development have long urged Australia to undertake reform that would lessen the burden on income tax by either raising the rate or broadening the base of GST.
The government has flagged income tax cuts in next month's budget but has repeatedly ruled out having another look at the GST.
