Australian politics was thrown into chaos on Friday as the seven federal MPs embroiled in the dual citizenship debacle awaited their fate as the High Court decided their eligibility.

Five federal MPs lost their seats including Deputy Prime Minister Barnaby Joyce, Deputy Nationals leader Senator Fiona Nash, One Nation Senator Malcolm Roberts, and Greens Senators Larissa Waters and Scott Ludlam, having been declared not validly elected due to holding citizenship of another country, and thereby ineligible to serve in Australian Parliament.

Independent Senator Nick Xenophon and Nationals Senator Matt Canavan have retained their seats.

As a result the Turnbull government has lost its one seat majority in parliament.

Joyce now faces a fight to regain the seat of New England, with a by-election expected to be called immediately.

According to reports, the earliest date a by-election can be held is 2 December.