Liberal MP John Alexander Resigns From Parliament

Liberal MP John Alexander has resigned after finding out that he’s a dual citizen and thus ineligible to sit in parliament.

Alexander’s father was born in Britain and never renounced his citizenship, thus conferring British citizenship on his son.

Australian elected politicians are constitutionally not allowed to hold a citizenship of any other nation.

Alexander said today that he wasn't sure he was definitely a dual citizen, but based on everything he knows he thought it fair to assume he is.

"Given what I have learned about the Constitution and understanding now of the High Court decision just a couple of weeks ago, I can no longer, with sufficient certainty, maintain the belief that I have held through my 66 years," he said at a press conference today.

"Therefore, it is my obligation that I must resign. That's what I will do."

The resignation will trigger a by-election in the Sydney seat of Bennelong, once held by John Howard.

He is the second lower house MP to resign over the dual citizenship furore after Barnaby Joyce — the deputy Prime Minister and member for New England — had to quit.

Alexander’s resignation means that the by-election will likely be held on December 16, just two weeks after Joyce’s northern NSW seat goes to the polls.

Alexander can run for the election, but needs to fully renounce his UK citizenship before nominating.

He indicated today that he would try and do so if possible.

"I will seek the support of my party to contest the by-election for Bennelong," he said.

With Alexander and Joyce gone, the Coalition government is down to a minority in the House of Representatives for the last two sitting weeks of 2017.

Alexander is the latest sitting politician to lose their position to the dual citizenship saga, with other including Joyce, Fiona Nash, Scott Ludlam, Larissa Waters and Malcolm Roberts.