Does Hanson-Young aspire to lead the Greens?
Sarah Hanson-Young is staying tight-lipped about whether she will throw her hat in the ring to be the new leader of the Australian Greens.
The party will pick a new leader tomorrow after Richard Di Natale's shock resignation this morning.
Victorian MP Adam Bandt has emerged as the frontrunner after Queensland senator, Larissa Waters, confirmed she was seeking support to remain deputy leader.
NSW senator Mehreen Faruqi may also run, but Tasmanian senator Nick McKim has ruled himself out as a contender.
Senator Hanson-Young, who has represented South Australia in parliament since 2007, has yet to speak publicly after Senator Di Natale's bombshell announcement this morning.
Sources have told The Advertiser she may nominate but it was unlikely she had the numbers to be leader.
Senator Hanson-Young has been outspoken on the River Murray, same-sex marriage, and education, had a swing towards her at the election, and recently won her prominent defamation case against former senator David Leyonhjelm.
The Greens may consider a co-leadership role, modelled by the New Zealand Greens Party, when they vote tomorrow.
Senator Faruqi has called for "co-leaders" and wants Greens members to have a say in the leadership vote.
"Selecting our new leader is a great opportunity to democratically involve members in the process. The party should be doing just that for this ballot," she wrote on Twitter.
The party has long been discussing whether its members, and not only elected MPs, should be involved in how the leader is elected.
Senator Di Natale has stepped down as leader effective immediately and will quit parliament to spend more time with his family when a replacement for his senate seat is found.
Senator Hanson-Young was unavailable when contacted by The Advertiser this morning.
Former Greens leader Bob Brown has not publicly backed a candidate but praised Senator Di Natale, saying he left the party in good shape.
"Richard's a fantastic politician, full of integrity, and I wish him well," Mr Brown told The Advertiser.
"I look forward to the party coming up with an equally brilliant person to lead us to the next election."
Mr Brown predicted the next Greens leader would be able to achieve a record vote at the next election, saying Australia had never needed the party more, given the Adani coalmine and climate change.
Senator Di Natale advised his party colleagues of his decision this morning.
In a statement, he said it had been a privilege and an honour to lead the Greens for four years but it had been a "tough, demanding job".
"My boys are nine and 11 years old and they have only ever known their dad as a busy, tired and sometimes grumpy politician," he said.
"As they grow up quickly to become young men, I want to spend more time by their side than a relentless political schedule allows."
Mr Di Natale said he was most proud of the party negotiating a carbon price with the Gillard Government in 2010, pushing for royal commissions into banking and the disability sectors, and the historic vote to achieve marriage equality.
"I don't know what comes next for me, but I intend to continue to make a positive contribution to the issues about which I have been so passionate for my entire adult life: Green politics, climate change, health, issues affecting First Nations people and tackling inequality," he said.
Former SA Greens Senator Robert Simms publicly thanked Senator Di Natale for his leadership.
"You will be greatly missed. Best wishes for this next chapter," he wrote on Twitter.