AUSTRALIA will spend $440 million on next week’s census. The census will ask about 55 questions, making it about $8 million a question. That is a lot more useful and a lot cheaper than the proposed $160m plebiscite on marriage equality.

The plebiscite will get an answer to only one question, and we already know what that answer is. Moreover, the answer is completely useless because MPs will not be bound by it and nor will the question contain any exact legislative words.

Someone should have thought of adding a marriage-equality question to the census if the Government was so keen on finding out the population’s opinion.

Not that even that idea would stop what is shaping up to be an ugly campaign. Just look, for example, at the rancor over the religion question in the census.

I’ll come back to that.

The plebiscite has already raised a few questions: its constitutional validity; its wording; and the nature of a “majority”.

Some constitutional experts doubt whether a compulsory vote on marriage equality, with the criminal sanctions of a fine, would pass constitutional muster as, in the words of the Constitution, “a law with respect to marriage”.

It might be too remote from the head of power and not even incidental to it. There are plenty of High Court cases on that – enough for someone to make a nuisance of themselves by lodging a challenge. Probably it will be someone who wants to delay or frustrate any hope of marriage equality, but it could be someone who wants marriage equality, but to achieve it without a plebiscite.

The people who mention the difficulty of the compulsory plebiscite being beyond power, however, have missed a couple of points.

There is a fair argument that the legislation could be characterised as a law “with respect to census and statistics”, to use the words of Section 51(xi) of the Constitution.

After all, it is collecting data (the number of people who support or oppose marriage equality) for the purposes of informing public policy (whether to change the definition of marriage in Australia.

Does it matter whether the statistics are gathered by demanding that people fill out a form at home or whether they are commanded to go to a polling booth for the information to be gathered?

There is a 2000-year-old precedent for this. Mary and Joseph had to go from Nazareth to Jerusalem to be counted. At least in Australia the statistical gathering stations (polling booths) will not be so far away.

Further, the High Court has held the Federal Parliament has an implied power for things of major national importance which are not explicitly stated in the Constitution, such as running the CSIRO or, perhaps, resolving fundamental national questions through plebiscites.

The wording is bound to cause strife unless done like a referendum where people vote on the precise constitutional (or in this case legislative) change.

And is the majority to be 50% of voters; 50% of the formal vote; or just more than the No vote?

To return to the census, we are already seeing how desperate and ugly a debate can get once you involve religion.

Clergy are urging people to state they are Christian even if they do not go to church or believe in all the dogma set out in the various Christian creeds. They argue that people should put down the religion they were brought up in culturally.

However, that argument might backfire give the revelations by the Royal Commission into child abuse of the culture of cover-up, particularly by the Catholic and Anglican Churches. Who wants to associate with that culture?

Surely, it is better to be ethical and state Not Religious, than associating with a religion through culture and family.

The other ugly argument is that the fewer Christians there are, the more weight will be given to the number of Muslims, with a consequent affect on funding, particularly education, as if there were policy by Google – the more hits you get in the census the higher up the funding rankings you go.

It is a silly argument given the tiny portion of Muslims in Australia, but the fact that it is being put shows the sort of idiocy that might ensue in a plebiscite campaign on marriage equality.

That is a very cogent reason for not having it, along with the cost, and the fact it is unnecessary because the Parliament has the power to legislate without it.

The High Court held in the ACT marriage equality case that the ACT law was invalid because the marriage power enabled the Federal Parliament to legislate with respect to all marriages (same-sex, polygamous or whatever), even though at least for now it had chosen to cover the whole marriage legislative field by determining that marriage is only between a man and a woman, so there was no room for any state or territory law to define marriage any other way.

If it is to be defined another way, only the Federal Parliament could do it, and it had the power to do so, the court held.

It is not like Ireland which required a constitutional change before a legislative one could go ahead.

This week Bill Shorten said he would take the matter of the plebiscite back to his party room. After all there has just been an election and the party room has changed. Malcolm Turnbull should do the same thing.

Tony Abbott’s divisive genius is still at work here, and Turnbull should call it out.

Remember, Abbott learned from John Howard – the master of divide and rule, who effectively put paid to the republic, even though it was supported by a majority.

We now have the efforts of many supporters of marriage equality effectively diverted to arguing against a plebiscite instead of putting their efforts into ensure marriage equality happens.

But, aside from calling out Abbott’s divisiveness, there is another reason Turnbull should scrap the plebiscite – self-preservation. If he does not and the Senate blocks it for him, he is going to find it very difficult to hold the numbers in the House of Representatives to use procedural tactics to prevent a Private Member’s Bill or an Opposition Bill from being voted upon.

Labor could easily insist on the party line for all procedural votes to bring such a Bill on, even if it allows a final conscience vote. And that is consistent with Voltaire’s principle. It would then only take a couple of floor-crossing Liberals (who are allowed to vote with their conscience) to force a parliamentary vote.

Turnbull would then face an invidious choice – snookered by Tony Abbott’s plebiscite.