In a stunning development, Deputy Premier Susan Close and Treasurer Stephen Mullighan have announced they will step aside from State Cabinet immediately and retire from parliament ahead of the March 2026 election.
The simultaneous announcements, made at a press conference in Adelaide today, mark the end of more than two decades of combined senior political leadership in South Australia. Premier Peter Malinauskas described the news as “really saddening” and admitted he was “taken aback” by the decisions.
Two Political Heavyweights Step Away
Deputy Premier Susan Close has served as a cornerstone of South Australian Labor for over a decade. First elected to represent Port Adelaide in 2012, she has held the deputy premiership since March 2022 and currently oversees critical portfolios including Climate, Environment and Water, Industry, Innovation and Science, and Workforce and Population Strategy.
Today marks an important day in our state’s political story.
Deputy Premier Susan Close and Treasurer Stephen Mullighan have shared with me their decision to not re-contest at the next election. They will also be stepping away from their Cabinet roles, a decision that marks the… pic.twitter.com/K7H8CP7vQJ
— Peter Malinauskas (@PMalinauskasMP) September 18, 2025
Close’s political journey began in environmental activism before transitioning to university administration and eventually state politics. She holds a PhD from Flinders University and previously worked as an executive in the SA Environment Department.
Treasurer Stephen Mullighan entered parliament in 2014 as the Member for Lee, becoming only the second Labor MP in history to immediately enter Cabinet. Since March 2022, he has served as Treasurer, alongside roles as Minister for Defence and Space Industries and Minister for Police.
Personal Decisions Drive Political Exits
Both ministers cited deeply personal reasons for their departures, with family considerations taking precedence over political careers.
Close revealed that watching her mother’s battle with dementia over the past four years served as a profound wake-up call. “Life is really short,” she explained. “I have been watching my mother disappear into dementia over the last four years, and it was for me an alarm bell reminding me that life is finite and precious.”
She emphasised her desire for freedom and new challenges: “I want to do something else. I want to have some freedom, and I feel I’ve given what I can to public life.”
Mullighan’s decision centred on family responsibilities following recent losses. “I’m in a position where I’ve lost both my parents and Antonia [his wife] has lost her father,” he said. “It takes a village to raise children and our village is a little bit smaller. I want to make sure while the kids are still young, and I’m relatively young, that I can be around more and be present as a husband.”
Deputy Premier Susan Close and Treasurer Stephen Mullighan have announced their retirement from politics, citing personal reasons.
📌 READ MORE: https://t.co/2WJW31KdlG pic.twitter.com/vm3P4NtKkb— The Advertiser (@theTiser) September 18, 2025
Premier’s Response and Political Implications
Premier Peter Malinauskas struggled to contain his disappointment at losing two of his most trusted colleagues and “close confidants.”
“This is a significant day in our state’s political history,” Malinauskas said, describing both ministers as having demonstrated “formidable intellect, incredible leadership, competence and loyalty.”
The Premier revealed that Close had informed him of her decision several weeks ago, while Mullighan approached him around the Labor party’s State Convention. “You could’ve knocked me over with a feather,” Malinauskas admitted regarding Mullighan’s announcement.
Impressive Track Records Leave Big Shoes to Fill
Both departing ministers leave behind substantial legacies across South Australia’s mining and resources sector and broader economic development.
Close has delivered significant education, environment and social policy reforms throughout her parliamentary career, including new STEM facilities for public schools and advocacy for three-year-old preschool programs.
Mullighan’s achievements as Treasurer include returning the budget to surplus, improving the state’s credit rating outlook, and delivering what the Premier described as “the nation’s best performing economy.” His infrastructure portfolio has overseen major projects including South Road upgrades, the Torrens to Torrens project, and the O-Bahn city access project.
Cabinet Reshuffle on the Horizon
The Premier announced he would reveal the new shape of State Cabinet tomorrow, as the government prepares for the March 2026 election without two of its most senior figures.
This represents the most significant reshuffling of the Malinauskas government since taking office in March 2022, creating opportunities for rising Labor MPs to step into senior roles.
End of an Era for SA Labor
The departures mark the conclusion of remarkable political careers that have shaped modern South Australia. Close’s seven and a half years as Deputy Leader of the SA Labor Party and Mullighan’s more than 22 years in various state government roles represent institutional knowledge that will be difficult to replace.
Their exits come at a time when South Australia’s resources sector continues to attract global attention and investment, making the timing particularly significant for the state’s economic future.
As the Premier noted: “It has been my immense honour and privilege to have worked so closely with both Susan and Stephen over the past decade.”
The political landscape in South Australia will look markedly different as the state heads toward the 2026 election, with two of Labor’s most experienced and capable ministers choosing family and personal fulfilment over continued public service.
