Combatants prepare for the Great Tax Battle

The scene has been set for a titanic struggle this week over tax reform.

The government is determined to force a vote in the Senate on the remainder of its company tax cuts.

It will also go to war with Labor and the crossbench over the $144 billion personal income tax plan. There can be no confidence that it will succeed in either venture, but that is no longer the point.

With five by-elections looming, the next two weeks of parliament have become all about positioning.

Scott Morrison has succeeded in creating a sense that there are exigent circumstances in having the PIT — an acronym that even the government has oddly adopted for the personal income tax plan — passed in this last sitting fortnight before the winter break.

The first phase of the tax cuts for lower income workers begins on July 1.

This is true. Mostly.

The greater component of the tax relief in the first phase comes in the form of the tax offset paid as a rebate at the end of the year — the year for the purposes of this package being 2019.

There is an argument that the change to the thresholds cannot be backdated to July 1 if the bill doesn’t pass before then. But this can be adjusted by the tax office throughout the year to compensate for a later start date.

The point is that the government doesn’t necessarily need to have the bill passed this week or next to ensure the mechanics of the package’s first year of operation. It could have it passed in September and still maintain the integrity of the policy.

The exigent circumstances are the five by-elections. And this is where the government hopes to wedge Bill Shorten.

If Labor sticks to its guns and refuses to pass the entire PIT package then the obvious government pitch to voters in Longman and Braddon is that Labor has refused immediate tax cuts for low-paid workers.

It is this optic that would also be weighing upon the minds of the Senate crossbenchers, who are yet to have any real skin in the game being played out by the two major parties.

Pauline Hanson’s spectacular but not unexpected meltdown two weeks ago has created a new ­dynamic in the Senate to be sure. The crossbench is now harder to read than Proust.

But it is unlikely that they will want to be the ones who ultimately carry the can for denying tax cuts, with July 28 now being a test run for a general election battle over tax.