Australia's High Court has ruled Deputy Prime Minister Barnaby Joyce will no longer be eligible to sit in the parliament as he held dual citizenship during the election, putting the ruling government's majority at risk. Joyce was among five lawmakers disqualified by the court on Friday, 27 October.

Citing the Australian constitution, which prohibits dual citizens from being elected, the High Court in Canberra ruled fresh by-election needs to be held for Joyce's seat. Joyce held a New Zealand citizenship at the time of elections but renounced it in August so he will be allowed to contest in the upcoming by-election.

The court ruling means Prime Minister Malcolm Turnbull's coalition, which holds a one-seat majority in the lower house, will be at risk forcing the premier to seek support from independent lawmakers.

"I'm not going to participate in it. I will concentrate on the people of New England. That is exactly what I was doing today. I will be talking to people in the streets, the supermarkets, the sale-yards, and making sure that service to them and my nation remains foremost in my mind," said Joyce, who argued he was unaware of his New Zealand citizenship before the elections, after the court's outcome. Joyce, born Australian, had citizenship in New Zealand through his father.

"I respect the verdict of the court. We live in a marvellous democracy, with all the checks and balances they have given us all the freedoms we see. I thank the court [for] their deliberations," added the disqualified deputy prime minister.

By-election for Joyce's seat is expected to take place on 2 December. Two other senators who were also under the scrutiny were allowed to keep their seats in the ruling.