The LNP polling popularity has been trending down since the introduction of the Carbon Tax.

A Tax scare campaign is a good election strategy ( Remember Keatings GST scare campaign).
However the strategy is for the SCAREY to occur at the election… not 18 months before the election.
Abbott’s strategy has been incredibly dumb and every time he mentions the Carbon Tax he is shooting himself in the foot. Gillard loves Abbott and she doesn’t want to loose him to a LNP leadership change.

France has fixed terms for all its three elected national positions: Presidency (5y), Assembly (5y), Senate (6y).

I can’t quite nail down the mechanism for how the dates are chosen but I would bet it is tightly delimited (especially with the Presidential and Assembly elections being close to each other). There are mechanisms (other than resignations — eg. de Gaulle; or death eg. Pompidou) to remove the President in the case of constitutional malfeance or inability (health etc), effectively an impeachment by a High Court. The President can dissolve a dysfunctional Assembly but again under tightly controlled conditions.
…………………….
The only reason not to have fixed terms is that the politicians have arranged it to maximize their political advantage — which is hardly a valid reason in a democracy. Rightly, the mechanism for removing a elected politician/government prematurely should require a very high bar.

I think Australia has definitively proven that short terms work against long term planning (in Oz 3 years but because of the ability of the government to call elections, the average term in Australia is actually closer to 2 years! yet another reason why it should be nixed.)

And yes Klewso, it should be 5 years (like France and UK). As much as I dread the thought of someone like Abbott getting a potential 5 years, the reality is it happens anyway: Howard ruled for almost 12 years. (Along with 5y fixed terms there should be term limits of two for PMs.) The psephologists will tell you that Australian voters mostly give a government two terms which means nominally 6 years but (as per above) is often 5 or even less — by itself this suggests that most people understand that one 3 year (or shorter) term is not enough to have proven their agenda etc. Of course, two consecutive terms adding up to 5 or 6 years is manifestly NOT the same as one fixed 5y term. Instead of concentrating on long term issues for the country they are forced into short-term, populist crap and bribes in a perpetual election cycle.

Commonsense suggests that four (4) yearly elections are suitable to all parties. It would consign to history the
media hysterics and the inability of any party to develop a and launch policy for evaluation and public scrutiny.

All sensible. Presumably you would keep Senate terms aligned with the Reps, so would you have them 4 or 8 years? I prefer 4.