HOW far should party discipline go? Not as far as certain proponents of same-sex marriage would like it to go in the Liberal Party. Nor as far as federal Labor MP Nick Champion has advocated in relation to opposing the GST.

With federal parliament resuming next week, the political scene is already noisy and fractious. The choice of former Army chief David Morrison as Australian of the Year quickly became the centre of sniping about political correctness. Invitations for Tony Abbott and Kevin Andrews to speak to right-wing outfits in America sparked predictable headlines.

The political mood of the Liberal Party conservatives hasn’t improved over the summer, and they are out prosecuting their cases. Former Senate leader Eric Abetz caused angst when he said that after the promised post-election plebiscite on same-sex marriage MPs would make up their own minds on how they voted in parliament. Cory Bernardi indicated he would certainly vote against changing the law.

Liberal campaigner for same-sex marriage Warren Entsch said: “It makes you wonder why we would spend millions of dollars on a plebiscite if you’re not going to respect the result. I find it rather bizarre.”

We don’t have to wonder why it is proposed to spend that money, when the issue should just be decided by a parliamentary vote. It was a fix conceived by Tony Abbott, as a way of resolving a party conflict and stalling the issue. Malcolm Turnbull later signed up to it as part of the price of leadership. Pure political pragmatism all round.

The question of MPs respecting the plebiscite’s outcome is a bit more complicated.

A “yes” vote would obviously have the Turnbull government moving to implement the result. On usual precedent, frontbenchers would be bound not to oppose that legislation.

But it is another story for Liberal backbenchers. They always have the right – and some exercise it from time to time – to cross the floor.

One can powerfully argue that if the people have spoken, a politician should heed their voice. Some Liberal backbenchers without firm views or even personally opposed would take their lead from a “yes” result. But if a few have very strong beliefs against, they should be able to vote accordingly – and couldn’t be stopped anyway.

It would probably not be many – and not enough to make a difference to the parliamentary outcome. If the plebiscite got through, it is as good as certain the legislation to implement the result would do so. On the ALP’s present policy, Labor’s MPs would have a conscience vote but they overwhelmingly would support it.

Critics of the outspoken Liberals should be more concerned about the plebiscite. While its prospects look good, the threat from the “no” case is always a risk. Opponents will be pulling out all stops.

On the Labor side, Champion, from South Australia, who is a shadow parliamentary secretary, this week made the startling suggestion that Labor’s national executive should “bind all members across the country” to oppose an increase in the GST.

Champion is critical of South Australian Premier Jay Weatherill for opening “debate on a measure so hostile to Labor’s traditional constituency and ideology”. “The SA government should rule out any support to lift the rate of GST and join federal Labor’s long term opposition to this unfair and regressive tax,” he wrote in The Australian.

Champion’s proposal is flawed on several grounds.

It might be a quibble but perhaps he should remember that parties change their minds on policy over time. As treasurer, Paul Keating proposed a broad-based consumption tax in the mid-1980s, though the push eventually collapsed.

More substantially, the idea that Labor’s extra-parliamentary organisation, in the shape of the national executive, should second-guess politicians is unacceptable.

ALP parliamentarians spent decades unshackling themselves from the excessive power of the organisation. To move back the other way would open a Pandora’s box, taking the ALP towards a past when MPs were much more at risk of being under the thumb of unelected players.

A premier should advance the policies he or she believes best for their state. Weatherill has canvassed a higher GST on the grounds (and condition) that it could help fund hospitals and schools.

The challenge posed by hospital funding has been underlined this week by the Australian Medical Association’s 2016 Public Hospital Report Card, which shows a stagnant picture. AMA president Brian Owler, releasing the report, said that “public hospital funding is about to become the biggest single challenge facing state and territory finances”.

The Victorian and Queensland Labor premiers are opposed to GST changes. The fact Weatherill is not in the Labor groove on this indicates some independent thinking.

Weatherill’s stance might be embarrassing for Bill Shorten, and at odds with the dominant Labor view. But he has made a substantial contribution to the discussion on taxation, whether one agrees or disagrees with his particular proposals.

Undoubtedly discipline is important in political parties. But it should not be turned into a tyranny of conformity.

Michelle Grattan, Professorial Fellow, University of Canberra

This article was originally published on The Conversation. Read the original article.