A political earthquake has struck the Australian Capital Territory after former Opposition Leader Leanne Castley dramatically resigned from the Canberra Liberals, accusing the party of fostering a “toxic culture” marked by bullying, intimidation, lies, and even an alleged threat of physical assault.

The resignation, announced on June 3, has sent shockwaves through ACT politics and triggered fresh scrutiny of a party that has spent more than two decades struggling to return to government.

Castley, who represents the electorate of Yerrabi, confirmed that she would immediately leave the Canberra Liberals and continue serving as an independent member on the crossbench for the remainder of the parliamentary term.

Her departure marks one of the most dramatic political exits in recent ACT history and raises serious questions about internal tensions within the Liberal opposition.

In a statement released shortly before the announcement, Castley delivered a blunt assessment of her experience inside the party.

“I have simply had enough of being part of an organisation with such a toxic culture,” she said.

“In the last 18 months, I have experienced bullying, intimidation, lies, and even a threat of physical assault.”

“I can no longer be part of an organisation which tolerates this conduct.”

The allegations immediately dominated headlines across Australia.

While political parties frequently experience internal disagreements and leadership disputes, allegations involving threats, intimidation, and workplace hostility represent a far more serious challenge.

Castley later elaborated on her concerns during media interviews, describing what she characterized as an ongoing campaign of undermining that had persisted throughout her leadership period.

“It’s not one person, it’s not one issue, it’s been an 18-month campaign,” she said.

“At some point I had to put a line in the sand and say, okay, I’m walking away.”

The former opposition leader indicated that the alleged threat of physical assault had been formally reported within party structures.

She also confirmed she was still considering whether to pursue the matter further through law enforcement channels.

However, she declined to publicly identify the individual involved.

“The party are aware,” she said, while refusing to name the person she alleges made the threat.

The resignation is particularly significant because Castley only stepped down as Canberra Liberals leader seven months ago.

Her leadership tenure itself was marked by considerable controversy.

After Labor secured its seventh consecutive ACT election victory in 2024, Castley was elevated to the leadership role as the Liberals searched for a path back to government.

The task was never going to be easy.

The Canberra Liberals have been out of government since 2001 and have struggled for years to establish themselves as a credible alternative to Labor’s long-running administration.

But internal divisions soon emerged.

One of the most contentious episodes involved senior Liberal figures Elizabeth Lee and Peter Cain.

Both were effectively frozen out of key decision-making processes and later suspended from the party room after crossing the floor during an Assembly vote concerning parliamentary sitting weeks.

The move sparked a fierce internal backlash and intensified existing tensions inside the party.

When Mark Parton replaced Castley as leader in November 2025, one of his first actions was to reinstate both Lee and Cain, a move widely interpreted as an attempt to restore party unity.

Yet the latest developments suggest many of those divisions never truly disappeared.

Castley’s resignation has effectively reopened long-standing questions about factional conflict, leadership instability, and internal culture within the Canberra Liberals.

Current leader Mark Parton strongly rejected suggestions that the party suffers from a systemic culture problem.

Speaking after the resignation, Parton acknowledged the seriousness of the allegations but disputed Castley’s broader characterization of the organisation.

“I reject the allegations about the toxic culture of the party,” he said.

“It’s a political party. It’s a robust environment.”

“There are people involved in this pursuit with very strong opinions who want to put those opinions forward, but I’m not sure that that translates to a toxic culture.”

Parton also emphasized that any complaints raised within the party are taken seriously and handled through appropriate internal processes.

The controversy deepened further when details emerged regarding the alleged threat of physical assault.

Canberra Liberal MLA Chiaka Barry later suggested that comments interpreted by Castley as threatening may have been misunderstood, describing the incident as a “misunderstanding” linked to tensions following parliamentary exchanges.

That explanation has done little to calm political speculation.

Observers note that even the existence of such allegations highlights significant tensions within the opposition ranks.

Meanwhile, ACT Liberal Party President Adam Morris expressed shock at the claims and publicly encouraged anyone with evidence of misconduct to come forward.

According to Morris, such behavior has “no place” within the party and should be investigated if credible evidence exists.

The fallout extends beyond internal party politics.

Labor ministers have also weighed in on the situation.

ACT Health Minister Rachel Stephen-Smith described the allegations as concerning and said that all elected representatives deserve safe workplaces regardless of political affiliation.

Her comments reflected a broader sentiment among many observers who argue that political disagreement should never escalate into bullying, intimidation, or threats.

For Castley, the decision appears to have been shaped by more than internal conflict alone.

In explaining her resignation, she pointed to the recent introduction of coercive control legislation as a reminder of why she originally entered politics.

The legislation had been one of her long-standing priorities.

According to Castley, working on meaningful reforms for the community reinforced her desire to focus on policy outcomes rather than internal party battles.

“That’s what the community wants to see from its politicians and that’s what I want to spend my time on,” she said.

She insists that leaving the Liberal Party does not mean abandoning the values that originally brought her into public life.

Instead, she argues that serving as an independent will allow her to focus more directly on the needs of her constituents.

“The people of Yerrabi deserve my full focus,” she said.

Her departure leaves the Canberra Liberals facing difficult questions at a crucial time.

The party has spent years attempting to rebuild after repeated electoral defeats.

Leadership changes, factional disputes, and public disagreements have frequently overshadowed policy debates.

Political analysts note that prolonged internal instability can make it more difficult for opposition parties to present themselves as viable governing alternatives.

For a party already facing significant electoral challenges, the latest controversy could prove particularly damaging.

The broader implications remain unclear.

Castley has ruled out joining another political party for now and says she intends to continue representing Yerrabi as an independent.

Whether her allegations lead to formal investigations or additional revelations remains to be seen.

What is already certain is that her resignation has exposed deep tensions within the Canberra Liberals and reignited debate about political culture, workplace conduct, and leadership accountability.

For ACT voters, the episode raises important questions about the future of the opposition and its ability to unite after years of internal turmoil.

For Leanne Castley, the decision marks the end of a turbulent chapter inside the party she joined in 2020.

For the Canberra Liberals, it may be the beginning of an even more difficult period of self-examination.

And for Australian politics more broadly, it serves as another reminder that the battles taking place behind closed doors can sometimes become just as consequential as those fought across the floor of parliament.