The Cook Islands Appeal Court is hearing a challenge over the win by the caretaker prime minister, Dr Robert Woonton, in his Manihiki electorate.
The chief registar says the court, which is sitting in Auckland, New Zealand, will be deciding on a point of law over whether there's a conflict between the Electoral Act and the constitution.
Terry Hagan says it centres around whether challenges can be made to voters on the grounds of what consituency they vote in.
"What it comes down to is that 96(3) of the Electoral Act precludes the filing of a petition, and what is being sought under the terms of the petition is that there were five electors that voted in Manihiki that now the complainant cannot lodge a petition against as to the validity of their votes."
The court will also be hearing points of law connected to four other electoral outcomes, including that of the former speaker, Sir Pupuke Robati.