The case was an influential decision concerning the construction of Section 44 of the Constitution and the meaning of "indirect pecuniary interest" in an agreement with the Commonwealth.

The High Court held that Bob Day's re-election to the Senate in July 2016 was invalid, since he'd had an "indirect pecuniary interest" in an agreement with the Commonwealth since at least February 2016.

[2] Day ran as a Family First Party South Australia Senate candidate at the 2013 federal election and was successful.

[4] Shortly after Day's resignation, the government announced that it would move in the Senate to refer to the High Court the matter of the validity of Day's election in July 2016 in regard to a possible breach of section 44(v) of the Constitution, which provides that a person who "has any direct or indirect pecuniary interest in any agreement with the Public Service of the Commonwealth" (and s 44 continues) "shall be incapable of being chosen or of sitting" as a member of either house of the Parliament—and it follows that they are ineligible to be nominated for election to either house.

The Court found that, since 26 February 2016 (although three judges were prepared to say 1 December 2015), Day had had an "indirect pecuniary interest" in an agreement with the Commonwealth, and thus was in violation of section 44(v).