From her own mouth she is condemned

"There will be no carbon tax under the government I lead" declared Julia Gillard shortly before the last federal election, that saw Labor cling to office after cobbling together an unlikely alliance with a Green, a former Green and two rural independents.

Like Kevin Rudd's 2007 commitment to being an "economic conservative", this declaration was aimed at reassuring the voters and heading off a scare campaign by the Coalition. And like Rudd's pledge, Gillard's promise has turned out to be quite untrue.

I'm sure Tony Abbott can hardly believe his luck. As well as being able to call the Prime Minister a liar, he can also run the "great big new tax on everything" line which frightened Rudd and resulted in the government ditching its Emissions Trading Scheme before the 2010 election.

As question time last week showed, Abbott, a former pugilist, is going to be an even more ferocious Opposition Leader than usual, continually looking to knock the government out by throwing vicious uppercuts and big overhand rights.

The stakes could not be higher for Gillard as the real question is whether her leadership can survive. Since Labor disposed of Kevin Rudd's Prime Ministership last year it is certain that if the tax is confirmed as a serious electoral liability, Gillard's leadership will be similarly terminated as part of a radical about-face for the government.

The newspoll figures just released confirm that Labor is in trouble as a result of the carbon price plan, with most voters opposed and Labor's scores in the primary vote and two party-preferred slipping badly. There is little doubt that winning over the public's acceptance will be an uphill struggle.

Some have compared Gillard's carbon tax to the GST, but the Howard Government gave the people the chance to vote on its GST proposal at the 1998 election. The better comparison is with Workchoices, as pointed out by Peter van Onselen. But even with Workchoices, the Coalition at least did not specifically promise not to bring it in. The circumstances in which Gillard has introduced her carbon tax no doubt aggravate the anger and betrayal felt by some voters.

It is probable that Gillard's decision to introduce a carbon tax reflects the desire within the ALP to increase its primary vote, which has hovered to low levels for over a year. But the Greens are determined to take the credit for the carbon tax, with Christine Milne claiming that it would not have occurred but for the Greens.

It would therefore appear that Gillard's move has only helped the Greens, with supporters of a carbon tax only more likely to continue voting for the minority party because of its success in achieving a price on carbon.

Meanwhile, the details of the scheme are yet to be worked out, and the Prime Minister must be hoping that enough people study the details once they are released, so that they understand how they will be affected and are no longer so angry or afraid. But the softer the scheme is, the less likely the Greens are to support it, and there's no way the tax can be passed without the support of the Greens. In that event, Labor will look like having stuffed up again, by announcing something without being able to implement it. And voters with long memories will remember the broken promise, resulting in Gillard's esteem within the electorate continuing to be eroded.

Gillard's about-face on the carbon tax reflects the differences between the ALP's main supporters: the suburban working and middle classes on the one hand and the inner-city progressives on the other. It was the former that Gillard was pitching to before the election, with her carbon promise, her supposed opposition to gay marriage and support for border security. Post-election and governing with the support of the Greens, Gillard has now committed herself to a carbon tax and was willing to accommodate the Green's aim to allow the territories to legalise gay marriage and euthanasia in a dramatic shift to the left.

Late last year, Michael Costa argued that Gillard's cosying-up to the Greens and the left agenda was a mistake. In typically blunt terms, Costa wrote that:

Labor will never be able to match the Greens in a rhetorical battle on so-called social justice. The Greens, with their pathological antipathy to capitalism and inherent contempt for the principles of sound public finance, will always claim that more and more are in need, and more should be done. With their mantra that things would be much better if Labor just stopped selling out to the capitalist system and its vested interests, the Greens will always try to wedge Labor.

Labor cannot win a war with the Greens if it is framed in these terms. Labor must reframe the debate to focus on the destructive social and economic consequences of Greens policies. The Greens need to be confronted rather than appeased. This is precisely why federal Labor's political deal with the Greens is so damaging. Gillard and her advisers have, by formalising a political agreement with the Greens, unnecessarily and irresponsibly legitimised them in the eyes of many ill-informed voters as a credible political force.

Most traditional Labor voters are not supporters of the Greens' policies. The Greens' policies on a range of issue, from taxation to law and order, would horrify that base. In short, Gillard has made a damaging political blunder that will haunt the party for many years to come.

Given that the Greens are taking all the credit and Labor all the punishment for the Government's embrace of parts of the Greens agenda, Costa would appear to be correct.

One has to wonder why Gillard has compromised so much with the Greens. Being to the left of the Labor party, the Greens were always going to support Labor in government over the Coalition. And if the Greens proved too obstructive they would be risk being later blamed for forcing Labor to an early election and helping install the Coalition in office, thereby strengthening claims that they are an irresponsible party. A campaign in the seats like the seat of Melbourne along the lines of "a vote for the Greens is a vote for the Liberal Party" would potentially be of devastating effect in terms of turning some Green voters back into Labor voters.

In any event, it's not as though there is any merit in a carbon tax right now anyway. Post-Copenhagen, it is clear that the world cannot agree to any concerted action on climate change, and nothing that Australia does can possibly make any difference to the climate given that we only responsible for a little over 1% of the world's emissions. Also, global temperatures have been remarkably continuous over the last decade, indicating that climate change action is not as urgent as some alarmists would have it.

Meanwhile, the tax will drive up energy prices, harm the economy and cost jobs. This is by definition a useless tax, that will harm Australia's interests and have at best a negligible environmental benefit.

Gillard may believe she is being politically astute by pandering to the Greens, but the inconsistency between her position now and her position before the election is clear. Similarly, Rudd's popularity slipped once he deferred his ETS plans, when he previously claimed that climate change "is the great moral issue of our times" and that "delay is denial". It is probably the inconsistency, which exposed Rudd as a politician lacking in courage and conviction, which discredited him so badly. Gillard has also changed position on climate change many times.

Gillard may feel that her Government needs to embrace a big cause in order for it to stop languishing and stand for something. But it appears she has chosen the wrong issue. Why not instead re-visit the Henry Review and implement more of its recommendations, in what will help strengthen rather than weaken the economy?

If this carbon tax is the demise of Julia Gillard, then the issue of climate change will have destroyed the leaderships of Malcolm Turnbull, Rudd and Gillard. That reflects that it is a potent and polarising issue, as well as the fact that it has been badly mishandled a few times.

Whilst Rudd was too strong in his rhetoric and then wimped out when his cause became less politically popular, Gillard promised before the election to not do what she is now doing. And that could well prove to be her undoing.