During the 2016 federal election, Prime Minister Malcolm Turnbull seemed to treat the contest as a cordial disagreement between gentlemen.

Mr Turnbull reportedly resisted ‘going negative’ during the campaign, while Opposition leader Bill Shorten and his election strategists had no such compunction.

Thanks in no small part to the ‘Mediscare’ element of its campaign, Labor brought the Turnbull government to within one seat of defeat. And as a result, Mr Turnbull learned an important political truth – negativity is significantly more powerful in politics than positivity can ever hope to be.

So as we head towards the upcoming rematch between Mr Turnbull and Mr Shorten, we can at least be sure of one thing – the next federal election will more closely resemble a cage fight than a meeting of your local Rotary club.

Another thing that has become even more clear this week is that the election cage fight will be all about tax.

Far from being a choice between Tweedledum and Tweedledee, as it was perceived to be during the Howard years, this election will feature a stark policy distinction between Labor and the Coalition.

While both claim to want to improve the lives of everyday Australians, they aim to do so in vastly difference ways.

The Opposition has promised to raise some taxes and cut or abolish other tax breaks so that it can increase spending on health, education and welfare.

The Coalition has claimed its plan to reduce taxes for business will boost the economy, thereby creating jobs and raising wages.

Both will probably offer personal tax cuts.

However, most voters are unlikely to ever read or hear such a polite explanation of those policies. Instead they’ll be treated to a never-ending slanging match in which the main contenders will use whatever rhetoric and false “facts” are available to politically kick, punch and gouge the eyes of their opponents.

We’ve had a preview of the grudge match this week in Canberra, where the government’s fact-lite scaremongering over the Opposition’s new dividend imputation policy – or “pensioner tax” – caused Labor to quickly exempt pensioners from the proposed abolition of cash refunds.

In response, the Coalition simply shifted gear to berate it as a “retiree tax” instead.

The government’s attack on Labor has two elements – the Opposition’s trustworthiness and its economic credibility. The Coalition claims Labor’s ‘backflip’ on dividend imputation shows the Opposition is inconsistent and undependable, and that it doesn’t adequately think through its policies.

And it points to Labor’s ‘tax and spend’ approach as confirmation of the Opposition’s economic ‘irresponsibility’.

Labor also continued to play dirty this week, using every opportunity to falsely claim the entire $65 billion company tax cut package is a handout to the ‘top end of town’ or ‘multinationals’ or ‘the banks’, when it includes cuts for all businesses including family small businesses with turnovers as low as $2 million.

Neither side seems particularly concerned with letting the facts get in the way of a fierce political stoush.

The PM committed this week to taking the second round of company tax cuts (for businesses with more than $50 million in turnover) to the election if they are not passed by the Senate before then. The tax cuts for businesses under that threshold have already been passed and implemented.

Labor in turn committed this week to scrap the tax cuts for bigger businesses, and there are media reports it may also reverse tax cuts (that is, increase taxes) for businesses with turnovers between $10 million and $50 million. Labor says it will make a decision on this after the May budget.

And so the scene has been set for the tax cage-fight election, which can occur any time from August this year.

If this past week is anything to go by, that fight will be down and dirty. But there’s another important lesson that neither leader should forget: as we learned in 2013, a successful cage fighter doesn’t necessarily make a good prime minister.