The jurisdiction is twofold: (1) on a petition to the Court by an individual with a relevant interest or by the Australian Electoral Commission, or (2) on a reference by either house of the Commonwealth Parliament.

At the constitutional conventions that led to federation of the Australian colonies in 1901, it was decided that election disputes would be determined by the courts, but the manner in which this was to be achieved was left to the new parliament.

[6][a] There has been debate as to whether the determination of disputed returns is consistent with the constitutional role of the High Court in exercising judicial power.

[7][8][9] The power of the Court of Disputed Returns was brought to the attention of the public following the 2013 federal election in which the Australian Electoral Commission lost 1,370 ballot papers in Western Australia.

In 2017 there was a series of parliamentary references to the Court of Disputed Returns, to determine the eligibility of a number of members of parliament found or alleged to be dual citizens, contrary to Constitution s 44(i).

[17][18] The admissible grounds for a petition are whatever "the Court in its discretion thinks just and sufficient", but are specified to include "illegal practices ... committed in connexion with the election".

[30] Thus in relation to the eligibility questions referred to the Court in 2017, in addition to the member of parliament and the Attorney General, only Tony Windsor, the unsuccessful candidate for New England, was given leave to appear.

[1] The High Court emphasised the extent to which errors or illegal practice may have affected the outcome of the election,[10] with the effect that only close contests give rise to petitions.

Barton J held that the election was void due to irregularities in the way the returning officers marked some votes and Palmer won the by-election.

In relation to the other challenges, O'Connor J held that while it was established that irregularities had occurred, these were insufficient to affect the result of the election where Ozanne had a majority of 1,645.

Barton ACJ held the Court of Disputed Returns did not have the power to require the Chief Electoral Officer to produce the documents to be inspected by Hedges.

[45][c] John Kean challenged the election of Nationalist Edwin Kerby, who had defeated Labor's Charles McGrath by just 1 vote.

[50] Darwin was an isolated town, overland access was by a dirt track that was rutted and often impassable,[e] with no railway,[f] nor airmail service.

[53] The grounds of the challenge were that (1) Asian and pacific islander people had voted without being naturalised Australians;[h] (2) that ballot papers were inconsistently treated; (3) that an unqualified person had purported to witness postal votes; (5) that there was a reduced turnout in some subdivisions due to the wet season and the difficulty of obtaining qualified witnesses.

[57] Henry Crittenden challenged the 1949 election of Gordon Anderson on the grounds that (1) as a Roman Catholic, Anderson owed allegiance to the Vatican State and was therefore disqualified by section 44(i) of the Constitution and (2) the general advertising expenses incurred by the Labor Party exceeded the £250 per candidate election expenses permitted.

[58] George Cole sought to challenge the 1964 Senate Election for Tasmania in which Bert Lacey was returned for the 5th and final seat.

The Senate referred the question of whether he was disqualified from sitting as having a pecuniary interest in an agreement with the Commonwealth to the Court of Disputed Returns.

The challenge to the 1975 Senate Election for South Australia was that large numbers of voters had been disenfranchised by having their names removed from the electoral roll.

[63] Ms Berrill's challenge to the 1977 election for the seat of Boothby was dismissed because the petition did not plead the facts alleged to have constituted breaches of the Electoral Act.

Mason J noted that the legislative policy that the Electoral Rolls were a conclusive record of the persons entitled to vote was "the product of the controversial and unsatisfactory history of Parliamentary review of disputed elections" and dismissed the petition.

Brennan J held that "the jurisdiction of the Court of Disputed Returns does not extend to the making of a declaration that the entirety of a general election is void".

Webster made 22 allegations of irregularities, including widespread electoral fraud and that an advertisement mislead the voters that Deahm was a Democrat Candidate.

[80] Ross Free challenged the election of Jackie Kelly on the grounds that at the time of her nomination she was (1) a dual citizen of Australia and New Zealand and (2) a full-time officer of the RAAF.

Brennan J declined to refer the matter to the Full Court to reconsider the correctness of the decision in Sykes v Cleary that a recount for a lower house seat "could result in a distortion of the voters' real intentions".

[81] Kelly subsequently conceded that she was incapable of being chosen because she was a full-time officer of the RAAF,[82] a concession that meant the Court did not need to consider the question of her dual citizenship.

There is some question as to the position of the RAAF as it can be comfortably read as part of the military forces, but it is harder to include it in the expression "navy or army".

The Court held in Sue v Hill,[91] that the United Kingdom no longer retained any legislative, executive or judicial influence over Australia and was therefore a foreign power.

On 7 November 2016 the Senate referred that question to the Court of Disputed Returns and Culleton was subsequently found to be disqualified from sitting on 2 grounds of section 44 of the Constitution.

[106] The second ground of disqualification was the decision of the Court of Disputed Returns that at the time of his election, Culleton, having been convicted, in his absence, of larceny, was "subject to be sentenced" for an offence punishable by imprisonment for one year or longer.

[109] The Full Court held that the financial benefit that Day obtained from the lease was an "indirect pecuniary interest" in an agreement with the Commonwealth.