On the day independent Kerryn Phelps was officially declared the winner in Wentworth, a shot was fired across Scott Morrison’s bows to remind him of the challenge of managing a now-hung parliament.

It came not from Phelps but from a longstanding crossbencher, the maverick Bob Katter, who holds the north Queensland seat of Kennedy.

Katter is a politician who creates a fuss in search of a reaction. And what better time than when Morrison is heading north, in his bus, on a campaign journey through Queensland, making announcements as he goes?

“Don’t think you have my vote,” Katter declared in the headline of Monday’s press release.

He said he would “not rule out” voting to refer Chris Crewther, Liberal member for the Melbourne seat of Dunkley, to the High Court to determine whether section 44 of the constitution catches him. Dunkley is a marginal Liberal seat that becomes notionally marginal Labor at next year’s election, under the redistribution.

Crewther’s issue is a shareholding in a biotech company, Gretals Australia, that is said to have received a benefit from the Commonwealth via grants. The now notorious section 44, which has caught a plethora of federal parliamentarians over citizenship issues, also says someone shall be incapable of being chosen for or sitting in parliament if they have “any direct or indirect pecuniary interest in any agreement with the Public Service of the Commonwealth …”

The eligibility of Home Affairs Minister Peter Dutton has also been questioned under this provision, in relation to issues around a family trust.

Katter said he was “considering” his position, declaring he thought the Crewther situation was “a lot different” from that of Dutton.

But the giveaway was Katter’s segue. “I’m not impressed with the government in their three months in office running around pork barrelling”. In particular, the government was not dealing with North Queensland issues, he said.

“It seems that there is little point in working with a government that has had three months to do something for the north when all they are interested in is pork barrelling to secure votes. Clearly this indicates they have no interest in really helping North Queensland.”

It’s hard to avoid the conclusion that Katter is thinking less about the Crewther situation and more about what he might extract for North Queensland. After all, only on Friday he dismissed backing sending either Crewther or Dutton to the High Court, declaring “politics is not about this sort of rubbish.”

Phelps earlier on Monday told the ABC she wanted to get more information on the Crewther and Dutton cases.

On her own position Phelps, a doctor, said that she had “high level legal advice” that she didn’t have a problem in relation to Medicare, because the rebate went to the patient not the practice.

Labor says both Crewther and Dutton should go to the High Court. The opposition would have to round up the votes of all six crossbenchers to have the numbers for referrals.

But a referral doesn’t mean the person has to resign while the case is on.

Given the closeness to the election, even if there were a referral followed by an adverse decision, it would not trigger a byelection.

In any event, Sydney University constitutional expert Anne Twomey doubts Crewther has a problem.

Twomey says that, on what we know, it appears Gretals Australia doesn’t have an agreement with the Commonwealth - any connection appears relatively remote.

“While Gretals may be a participant in an Australian Research Council linkage grant, it is the University of Melbourne which has the agreement with the Commonwealth and receives the funding, not Gretals,” she says.

Michelle Grattan does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.