FAMILY First Senator Steve Fielding has killed Tony Abbott's proposed carbon tax plebiscite, calling it an "$80m glorified opinion poll".

Despite two meetings yesterday with the Opposition Leader over the detail of the proposed plebiscite, Senator Fielding decided overnight to reject it.

It is believed Mr Abbott's admission yesterday that he would not be bound by the plebiscite if the people said they wanted a carbon tax, tipped Senator Fielding against it.

"What we've got here is a political stunt which will waste taxpayers' money and achieve nothing," Senator Fielding said.

"It's basically a glorified opinion poll created over the weekend to give the Coalition some air time before the change in the makeup of the Senate.”

"Its an $80m political stunt that even Tony Abbott has said is not binding.”

"Last week the Coalition argued that the Government shouldn't be allowed to spend taxpayers' money on spruiking a carbon tax because it didn't yet exist, so how can we have a plebiscite on a policy that hasn’t even been finalised.

Senator Fielding, who will finish his six year Senate term on June 30, said Mr Abbott's proposal seemed haphazard and not properly considered.

South Australian Senator Nick Xenophon was prepared to support the plebiscite if the question was "less loaded" but with the Greens and the Government opposed to it, Senator Fielding's rejection means the idea will not pass.

Mr Abbott was trying to make the Government hold a plebiscite on the carbon tax before Parliament votes on it.

Senator Xenophon, who forced the SA Parliament to hold an electricity sale plebiscite in similar circumstances 13 years ago, said he would support the move if there was a more objective and "less loaded" question.

"As a general principle, you should (ask the people)," he said.

"But the question can't be loaded, it should be about the specifics, not slogans."



But Mr Abbott's admission that he would not be bound by the people's verdict is a surprise own-goal after taking the moral high ground on the question of democratic accountability.

He confirmed that position in Parliament saying he would oppose the carbon tax in opposition and rescind it in government.

That supported the Government's claim that the plebiscite was nothing more than an "$80 million stunt" in which Mr Abbott claimed to be calling for the people to decide the matter but had no such intention.