Why did Australia just kick its deputy PM out of parliament?

Barnaby Joyce, Australia’s deputy prime minister and the leader of the National Party, was removed from government Thursday after the country’s High Court ruled his election was invalid due to dual Australian and New Zealand citizenship.

The decision robs the center-right coalition, comprising the Liberal Party and the National Party, of its one-seat majority in the lower chamber.

The court said four senators — Fiona Nash, Larissa Waters, Scott Ludlam and Malcolm Roberts — were also wrongly elected for holding dual citizenships from Canada, Britain and New Zealand. Waters and Ludlam had already resigned over the scandal, which has gripped Australia since July.

Australia’s constitution bars dual citizens being elected to public office.

Joyce, who has been elected five times in federal votes since 2004, claimed until recently he did not know he held dual citizenship. The lawmaker renounced his New Zealand citizenship in August, and will now contest a local election on December 2. He is expected to win back his seat.

“I respect the verdict of the court,” Joyce said, adding he “felt in his gut this is the way it was going to go.”

The ruling is a slap in the face for Prime Minister Malcolm Turnbull, leader of the Liberal Party, who had been bullish over the case. “The leader of the National Party, the deputy prime minister is qualified to sit in this house and the High Court will so hold,” Turnbull said in August.

The ruling increases pressure on the minority coalition government to maintain control of parliament. However, at least one independent MP, Cathy McGowan, has already pledged her support for the coalition, making a no-confidence vote unlikely anytime soon.

The constitutional ban on dual citizens holding elected office, which dates back to the 1900s, is unlikely to be challenged.