Doubts about the future of FuelWatch have lead to speculation the Alcopops tax may also struggle to pass the Senate.
Two key Senators have pulled support for the petrol pricing website, forcing Health Minister Nicola Roxon to defend the pre-mixed alcohol tax.
Ms Roxon has told the National Press Club 1.1 million litres less alcohol is being consumed in Australia since the tax was introduced.
“If those figures are right, that our measure is working, it means the industry has a clear reason to be opposed to it because it does reduce their sales.
“I would have thought, and I certainly will invite every senator, and I certainly invite to the Liberal opposition to look very closely as to where these figures are coming from and which figures are credible.”