GST campaign not political ploy: Shorten

Opposition Leader Bill Shorten has brushed aside suggestions a possible hike in the GST is the only weapon Labor has to attack a popular government.

The Turnbull government won't rule in or out any idea - including changes to the GST - for its review of the tax system.

Mr Shorten denied Labor's anti-GST campaign was a political ploy, telling reporters in Canberra on Thursday the government was "gagging" to increase the impost to 15 per cent.

Labor had every right to focus on the harm any "dumb" GST increase would create for the less wealthy.

"The fact that this conversation, the fact the Liberal plans for the GST have not been ruled out means Australians have a legitimate question for Malcolm Turnbull," Mr Shorten said.

"You can't turn on the TV without seeing some conservative commentator saying the GST is going to be the solution for all of the world's ills."