Australia’s oldest micronation – the Principality of Hutt River – has been ordered to pay more than £1.8 million in taxes after a judge dismissed its legal claims to sovereignty as “gobbledygook".

The ruling by the Supreme Court of Western Australia came just four months after the His Royal Highness Prince Leonard I, the 91-year-old self-proclaimed ruler of the province, abdicated.

The court ruled that Prince Leonard, or Leonard George Casley, and his son Prince Wayne, or Arthur, will have to pay unpaid income tax from June 2006 to November 2013.

Justice Rene Le Miere dismissed Prince Leonard’s claim that he and his late wife Princess Shirley were “non-residents” of Australia for tax purposes.

He dismissed the Prince’s "strange pseudo-legal straw man theory" (which suggests that an individual has two personas and their debts and legal responsibilities belong to the 'straw man' rather than the physical person), saying the legal submissions for the micronation ranged from “merely irrelevant to bizarre”.