Liberals at war with selves on GST: Bowen

Shadow treasurer Chris Bowen says the Liberal Party is at war with itself over a possible increase to the GST.

Prime Minister Malcolm Turnbull says he's yet to be convinced that raising the GST rate to 15 per cent is the way to deliver tax reform, but Mr Bowen insists that such an increase is in the DNA of the Liberal party.

"We know that's what Malcolm Turnbull and (Treasurer) Scott Morrison really want to do. The question is whether Malcolm Turnbull has the political courage to take on his own backbench worried about their seats," Mr Bowen told reporters in Sydney on Sunday.