Scott Morrison is a command-and-control kind of guy, as he sought to show this week.

He told his backbench to keep their opinions in line or internal, appointed a man he’s personally close to as his new head of the Prime Minister’s department, and put the public service in its place.

But he also discovered that, even when an election win gives you great authority, this only operates up to a point, at least with your frisky parliamentarians.

It is not that the post-election Coalition party room is trying to undermine Morrison, as the right wing did with Malcolm Turnbull. It’s that some are intent on venting their opinions, to make a splash or perhaps, in some cases, because they think they should be higher up the ladder.

After all, they might ask, doesn’t the Liberal party (when convenient) boast that its MPs are on a long rein? Isn’t its mantra freedom of speech? And where is it written that the meek shall inherit advancement?

Liberal backbenchers at the moment are especially focused on superannuation, with a number speaking out against the legislated future rise in the superannuation guarantee, despite the government sticking by it, at least at the moment.

In his maiden speech on Wednesday, new NSW Liberal senator Andrew Bragg went a lot further. “I would change direction. Super should be made voluntary for Australians earning under $50,000,” he said, even suggesting that maybe it should be voluntary for everyone.

For his trouble Bragg, well known for his forthrightness, was publicly slapped down by Finance Minister Mathias Cormann. Asked if he agreed with Bragg, Cormann said in the Senate: “The answer is no. And I’ve told him that privately. […]And now publicly.”

Read more: View from The Hill: Morrison cracks the whip

More generally, the voices coming from the backbench about the guarantee might be regarded as something of a canary-in-the-mine ahead of the government’s proposed review of retirement income.

Bragg wasn’t the only Liberal backbencher to be given short shrift. When Craig Kelly, perennially vociferous, suggested looking at including the family home in the pension assets test, Treasurer Josh Frydenberg instantly shut down that thought bubble.

It is not clear what, if anything, the government might put out of bounds for the retirement income inquiry.

The planned review follows a recommendation from the Productivity Commission which called for “an independent public inquiry into the role of compulsory superannuation in the broader retirement incomes system”. The PC said this should happen before the rise in the guarantee, which now stands at 9.5%. From mid 2021 it starts to phase up to 12% in 2025.

The review could open a Pandora’s box. Asked on Thursday about its scope, Morrison hedged, indeed sounding less than enthusiastic about the whole exercise: “Reviews look at all sorts of things, but they are reports of reviews, not of the government”.

That’s true, but their recommendations can cause a lot of angst for a government.

Retirement income is one of the most sensitive policy areas – a point underlined by the Coalition’s 2016 election experience with superannuation changes and the political cost to Labor of what its opponents successfully dubbed its “retirement tax”.

If, depending on the terms of reference, the review urged abandoning the superannuation guarantee rise (already previously delayed by the Coalition), and the government decided to go down that path, this could set up a clash on retirement income at the next election.

Read more: Politics with Michelle Grattan: Centre Alliance's Stirling Griff on Newstart

While the latest chapter of the superannuation debate is just heating, the much simpler argument about Newstart continues to boil. Newstart’s paucity has been acknowledged by business leaders, John Howard and Barnaby Joyce, among many others. This week Western Australian Liberal senator Dean Smith added his voice.

On Thursday the Senate referred to a committee the adequacy of Newstart and related payments, with a report to come early next year. Notably, the reference was supported by Centre Alliance, One Nation and Jacqui Lambie.

Having just legislated $158 billion in tax cuts, even ministers are embarrassed about Newstart; they hate being asked whether they could live on $40 a day. But welfare payments are well down the scale of this government’s priorities, and it will not contemplate a boost that would eat into the projected surplus.

Nevertheless, the pressure won’t abate and it will be hard for the government to avoid doing something by the time the next budget comes around.

Senator Stirling Griff, from Centre Alliance, which holds crucial votes for the Coalition’s legislation in the Senate, says his party is willing to use its muscle in its negotiations to try to force the government to act, even if an increase is modest.

Read more: Morrison brings his own man in to head the Prime Minister's department

Morrison’s naming this week of a new head for his department did not come as a surprise. Prime ministers these days like to have their own man in this job (no woman has headed the department), and Morrison has a long association with Phil Gaetjens, who moves from treasury. The election result was its own miracle for Gaetjens, who would have been sacked if Labor had won.

What was more notable was the message Morrison sent to the bureaucracy. Essentially, it is one that downplays the public service’s role as a generator of policy ideas and sees it primarily as implementer and deliverer.

Asked about its advisory role, he said: “It is the job of the public service to advise you of the challenges that may present to a government in implementing its agenda. That is the advisory role of the public service. […] But the government sets policy. The Government is the one that goes to the people and sets out an agenda”.

There was a rather different emphasis in the farewell message from outgoing secretary Martin Parkinson, who encouraged his department’s staff “to have a view, be curious, understand what is happening at the forefront of policy and policy-related research, engage widely with stakeholders from all parts of the community, and be resolutely committed to advocating for truly evidence-based policy.”

In describing his view towards the public service Morrison, who loves a good slogan, has produced a new one, “Respect and expect”. A few bureaucrats might be thinking there’s more “expect” than “respect” in the PM’s attitude.