Australian Deputy Prime Minister Barnaby Joyce and four other Australian MPs have been ruled ineligible for election to parliament due to their dual nationality.
Barnaby Joyce was one of seven politicians affected by a High Court decision which disqualified him because he held dual citizenship when he ran for election a year ago.
"The decision of the court today is clearly not the outcome we were hoping for but the business of government goes on", Prime Minister Malcolm Turnbull said this afternoon.More news: President Uhuru Kenyatta calls for peace before repeat polls
The decision deals a blow to Prime Minister Malcolm Turnbull's Liberal-National coalition, which has a one-seat majority in the lower house.
Joyce could stand in a by-election, having renounced his Kiwi citizenship. A no-confidence vote would require all independent and crossbench lawmakers to turn against the government.
Members of Australia's national parliament can't be citizens of another country, according to section 44 of the country's constitution.More news: Rhian Brewster dedicates hat-trick to birthday boy team-mate Panzo
Most of the disqualified MPs were considered born to Australian parents overseas, or had been born in Australia to a foreign parent.
That this turn of events was caused by New Zealand makes it sting even more for the Australian government, which previously accused its closest rival of "conspiracy" against it.
Asked whether he was still a cabinet minister, Mr Joyce said: "Right now I'm not even a candidate - you have to be endorsed to be a candidate".More news: Spanish PM aims to take over Catalan govt; residents aghast
In July, two senators in the Australian Greens stepped down from their positions after discovering they were a New Zealand and a Canadian citizen respectively. The senator had already renounced his New Zealand citizenship before the election, but the case led to politicians and the media accusing other lawmakers of violating the constitution. He was born to Cypriot- and Greek-born parents and checked with both embassies to ensure he wasn't a citizen of those countries.