The Turnbull government is facing minority status and a difficult by-election after the High Court found the entire leadership of the National Party -- Deputy PM Barnaby Joyce and Nationals deputy leader Fiona Nash -- ineligible to stand at the 2016 election, due to their citizenship status under section 44 of the constitution.

The decision -- which the Prime Minister strongly insisted in Parliament would not happen -- plunges his government into another crisis in a week in which Employment Minister Michaelia Cash has faced pressure to resign in response to the AWU raid debacle.