Larissa Waters quits as Greens senator over dual citizenship with Canada

Larissa Waters has resigned from the Senate after revealing she holds dual citizenship with Canada.

The co-deputy leader’s resignation comes after Greens senator Scott Ludlam discovered he held dual citizenship with New Zealand and resigned last week. The constitution bars dual citizens from eligibility for election, unless they can show they have taken reasonable steps to sever foreign ties.

Waters was born in Canada to Australian parents who were studying overseas and came to Australia when she was a baby, growing up in Brisbane. She has not returned to Canada since she was 11 months old.

Her resignation means the Greens will be down two votes in the Senate for at least a short period of time, affecting the balance of power and potentially making it easier for the government to pass legislation.

Parliament will resume in early August after the winter break, and a Senate vote has been deadlocked for months on the Turnbull government’s plan to deregulate media ownership regulations.

The shift in the numbers in the Senate could create a useful window of opportunity for the Coalition. But a key Senate powerbroker, Nick Xenophon, pointedly warned the government against abusing its temporary numerical advantage in the Senate.

“No party should opportunistically abuse the situation while replacements are being chosen,” Xenophon told Guardian Australia.

“If people start abusing the situation as that would set a bad precedent with a long term poisonous effect on the operation of the Senate.”

A spokesman for the One Nation leader, Pauline Hanson, echoed Xenophon’s sentiments. He said One Nation would “caution” the government about maximising its moment of opportunity in the upper house.

The Greens said on Tuesday afternoon they had secured agreement from the Turnbull government to have the two votes “paired” until the Senate vacancies are filled.

The Greens leader Richard Di Natale acknowledged his party had chalked up a “terrible month” – with infighting triggered by the Gonski 2.0 schools funding package, and the resignation of two high profile senators because of eligibility questions.

Di Natale said he had taken steps to ensure the administrative oversights by Ludlam and Waters were not repeated with future Greens candidates.

He said he had asked the party co-convenors to “strengthen our governance, improve our internal processes and we make sure that this never happens again”.

“There is no question here – I won’t sugar coat it – we need to make sure that our internal party processes are up to the challenge,” Di Natale told reporters in Sydney.

“We have to improve our governance. We have to strengthen our internal processes and we have to make sure that this doesn’t happen again”.

Di Natale said he had learned about Waters’ dual nationality last Friday, and he signalled clearly he wanted her to return to politics. “As far as I am concerned, I would welcome her back to the parliament with open arms”.

Waters said it was with “shock and sadness” she learned she was a dual citizen.

“I had not renounced since I was unaware that I was a dual citizen. 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,” she said.

“I am deeply sorry for the impact that it will have.”

Waters had been told by her parents she had the right to become a Canadian citizen but it would be revoked once she turned 21. She decided not to pursue it and assumed she only held Australian citizenship.

Waters “wholeheartedly” apologised to the people who had elected her and hinted her political career was not over.

“The challenges we face as a nation are still so great, and I will not be stepping away from them,” she said.

“I have spent my working life protecting the environment and helping the community have better say in decision making, and that will not cease. We must stop the Adani mega-mine, and we must support women to be free from violence, sexism and pay discrimination.

“While my future remains uncertain, I have more to contribute and will be talking with my party about what lies ahead. Whatever the outcome, I will always work for gender equality and to protect the environment.”

Waters was elected to the Senate in 2010 and recently made headlines as the first woman to breastfeed in the Australian parliament.

Her departure will trigger a Senate countback which could install the next candidate on the Greens ticket for Queensland, Andrew Bartlett, in the parliament. Bartlett was a member of the Senate for the Australian Democrats from 1997 to 2008 and held the leadership from 2002 to 2004.

Bartlett released a statement saying he was devastated by Waters’ resignation and she had been a strong and effective advocate for the Greens.

“My immediate focus is on working with the many thousands of wonderful members and supporters of the Greens in Queensland to work through this situation so that we can continue to present an effective alternative to the establishment parties who fail our community and our environment so badly,” he said.

“The party’s membership will be having many conversations over the next few days as we process what has happened and determine what is the best way forward to ensure we remain a strong voice for the essential values the Greens promote.”

He said the Queensland Greens would continue to focus on running a strong state election campaign with a real chance of winning seats off both Labor and Liberal parties, as well as the immediate opportunity of the Ipswich mayoral byelection.