Updated

Australia's High Court will soon rule on whether seven lawmakers including the deputy prime minister and two senior ministers are eligible to sit in Parliament in a case that threatens the conservative government's slender majority.

The court will announce its decision on Friday. Prime Minister Malcolm Turnbull says he is confident the judges will not take a literal interpretation of a 116-year-old section of the constitution that bans "a subject or citizen of a foreign power" from sitting in Parliament.

The fate of Deputy Prime Minister Barnaby Joyce is most crucial to the government.

If the court rules that he was illegally elected due to New Zealand citizenship he inherited from his father, the ruling coalition could lose its single-seat majority in the House of Representatives, where governments are formed.