The review, led by former NSW Liberal premier Nick Greiner and former Victorian premier John Brumby, was called for by Treasurer Wayne Swan in March following complaints by Western Australia about the fairness of the system in dividing the GST pool.
But Mr Greiner's review looked beyond those parameters and found the GST to be failing, and called for a debate about its rate and scope, News Limited reported.
Ms Gillard on Saturday flatly denied any plans to increase the GST.
"We won't be raising the rate of the GST. We won't be broadening the base of the GST," Ms Gillard told reporters in Sydney.
"In the past I've ruled out any increase to the GST and I rule it out again today."
Ms Gillard said she had asked the report's authors to look at the question of the distribution of the GST and she would be analysing the results of that inquiry.
