Australian Greens co-deputy leader Larissa Waters has resigned from politics, because she has dual citizenship. She's the second person from the party to resign in less than a week.
Ms Waters is a citizen of both Australia and Canada, and was elected in 2010. Under the Australian constitution she cannot legally be a member of the Australian Parliament.
"It is with great shock and sadness that I have discovered that I hold dual citizenship of Australia and Canada," Ms Waters said on Tuesday.
It comes less than a week after Greens co-deputy leader Scott Ludlam also resigned, when he also found out he had dual citizenship.
"After Scott's shock discovery, I immediately sought legal advice, and was devastated to learn that because of 70 year old Canadian laws I had been a dual citizen from birth, and that Canadian law changed a week after I was born and required me to have actively renounced Canadian citizenship," Ms Waters said.
Ms Waters is a Queensland senator and made global headlines this year for being the first woman to breastfeed in a federal Parliament.
She assumed that as she moved to Australia from Canada as a baby she was naturalised as an Australian citizen. She was born in Canada while her parents were studying and working there briefly, and after leaving as a baby she has never returned.
"Obviously this is something that I should have sought advice on when I first nominated for the Senate in 2007, and I take full responsibility for this grave mistake and oversight. I am deeply sorry for the impact that it will have."