Prime Minister Malcolm Turnbull and Dr David Gillespie. Credit:Elesa Kurtz "I have no leases or deals with Australia Post," Dr Gillespie told Fairfax Media. But UNSW constitutional law expert George Williams believes Dr Gillespie could still be in trouble – particularly if the High Court settles on a broad definition of "indirect pecuniary interest" in the Bob Day test case. In that scenario the government should seek "urgent legal advice" about Dr Gillespie's eligibility, he says. "This does raise questions, there's no doubt about that," Professor Williams said. "These arrangements could certainly constitute an indirect pecuniary interest. I think there is an arguable case here."

Assistant Health Minister David Gillespie with former Liberal leader Tony Abbott. Credit:Port Macquarie News If Dr Gillespie was referred to the High Court and subsequently disqualified it would spark a byelection in his seat of Lyne. The Nationals would be likely to retain the seat but it would still be an enormous political headache for Prime Minister Malcolm Turnbull. Labor's legal affairs spokesman Mark Dreyfus has written to Attorney-General George Brandis about the situation, saying any doubts about Dr Gillespie's eligibility are "a very grave matter", given the finely-balanced Parliament. "This would not only affect Mr Gillespie but would imperil the government's majority and further weaken the Prime Minister's grip on power," he said in the letter. "I seek your urgent confirmation as to whether you have sought any advice from the Solicitor-General about this highly concerning matter, which raises questions about the constitutional integrity of the government."

Constitutional law expert Anne Twomey, from the University of Sydney, agrees the outcome of the Bob Day case will be critical in determining whether arrangements such as Dr Gillespie's are allowed. "It will depend very much upon the principles the court applies," Professor Twomey said. "For example, it might limit the application of the provision to cases where there is a risk of the government using the pecuniary interest to influence the member or where the member is using his or her office to obtain benefits from the government. We will not know until the Day case is decided." However Professor Twomey says contracts that don't personally involve the MP are less likely to breach section 44(v) "as it would not be likely to fall within the mischief that the provision was directed at". Section 44(v) of the constitution says any person who "has any direct or indirect pecuniary interest in any agreement with the Public Service of the Commonwealth otherwise than as a member and in common with the other members of an incorporated company consisting of more than 25 persons shall be incapable of being chosen or of sitting as a senator or a member of the House of Representatives".

The section is an anti-corruption measure, designed to stop people sitting in Parliament and at the same time making money through contracts with the Commonwealth. But it's also imprecise, and the limits of what's meant by "indirect pecuniary interest" have never been tested by the full bench of the High Court. The court is considering whether former Family First senator Bob Day was ineligible to be elected because he had an indirect financial interest over a taxpayer-funded electorate office leased to the Department of Finance. The government was given legal advice his arrangements could have breached the section. The case returned to the High Court on Tuesday. Comment on Dr Gillespie's case has been sought from Attorney-General George Brandis. Follow us on Facebook