With just over a month to go to the state election, Victorian politics is gradually easing into campaign mode. Yesterday saw the debut of the Liberals’ first TV ad, attacking Labor’s profligate spending on government advertising.

Clearly a major part of Ted Baillieu’s strategy is to portray the Brumby government as not just incompetent but morally questionable. And Labor often seems to play right into his hands: as with its move to set up a front group with the business community to pressure the Liberals over preferencing the Greens.

A strong Green vote is more likely to be an asset to Labor than a liability; the evidence suggests Green voters are more likely to come from the Coalition and give preferences to Labor than the other way around (although the effect is small either way: most preferences just go back to where the voters came from). Moreover, the Greens presence highlights issues that tend to play in Labor’s favor. But the Labor machine, whose apparatchiks are concentrated in the inner-city seats the Greens threaten, clearly doesn’t see things that way.

The Liberals, at least for the moment, have the luxury of not being distracted in this fashion. No Liberal seats are in any real danger from the Greens, although that could well change by 2014. If Labor chooses to spend its time and resources fighting the Greens in the inner city, that’s a double bonus for Baillieu: it gives him a clearer run in the outer-suburban marginals he needs to win, and it will make the Greens less likely to side with Labor should they end up with the balance of power.

Labor cares a great deal about whether the Liberals give preferences to the Greens, but for the Liberals it shouldn’t be a matter of much importance. Having some Greens in the lower house to complicate matters would certainly work to the Liberals’ advantage, but what they really need is support in marginal seats — most of which are a long way from Richmond and Brunswick.

If playing hardball with the Greens improves their chance of getting a preference deal, then of course that’s what they should do — and that means the Liberals have to credibly threaten to preference Labor, or to run an open ticket. They’re not likely to get much from the Greens in any case; on the other hand they’re certainly not going to get anything useful from the ALP, so they’ll have to be realistic about what a preference deal might achieve.

Both parties also need to be aware of the risks of being perceived to be too cozy with the Greens. This was the argument yesterday of Craig Ingram, the conservative independent MP for Gippsland East, who said the Coalition would “cop enormous grief” from his constituents if they preferenced the Greens in the inner city.

Ingram, the last survivor of the trio of independents who terminated Jeff Kennett’s career in 1999, is also thinking about his own position in a possible hung parliament, saying “he would prefer to support a government that didn’t need the Greens’ votes”. But as he evidently realises, his power in such a situation would probably be negligible.

In an even-numbered house of parliament (Victoria has 88 lower house MPs), a single independent has very little leverage. Even if the major parties split 44-43, the independent has no real choice — they can either allow the party with more seats to form government, or create a deadlock and get blamed for it. Not surprisingly, they invariably do the former.

So if Ingram and a single Green MP are returned, and the others split 43-all, Ingram and the Green would be the kingmakers — but only if they act together, which is the very thing Ingram says he doesn’t want to do.

In any other situation, whether there are multiple Greens or none, his vote will basically be irrelevant.

The Greens, however, just might emerge in a position of power — but only if Baillieu can first make up the eight or ten seats he needs to be within striking distance. Odds are he can’t, but if Labor keeps its eye off the ball for long enough, you never know.