Jane Garrett – the former cabinet minister who refused to back Daniel Andrews' controversial industrial deal with the firefighters union – felt the full, shocking brunt of it last Tuesday.

Andrews had just been whacked by yet another leak to the media: this one revealing an adviser had last year warned that union boss Peter Marshall's behaviour towards Garrett "crossed the line". It appeared to contradict a public claim from the Premier that he hadn't received any complaints.

Labor MPs shuffling into the stuffy caucus room on the second floor of state Parliament were in no doubt about who was to blame for the story. Nor were they in the mood to hold back.

One by one, for about an hour, more than half of the caucus rose to speak, calling for unity and an end to the destabilisation. Victorian Treasurer Tim Pallas began, telling the meeting he wouldn't be naming names, but anyone working so obviously against the interests of the government should consider their position. Rookie backbencher Nick Staikos then got up, saying he would "not be as kind", before accusing Garrett of being the leaker.

All the while, Garrett sat at the back of the room, enduring the character assessments in silence.

For a rising star of the Labor Party, how exactly did it come to this?

Not that long ago, Garrett was one of the ALP's top hopes: social justice warrior, darling of the union movement, potential future leader. Now, the Brunswick MP is stuck in a quagmire, loathed by many colleagues, yet admired by the public for taking a principled stand against an industrial deal she believed was outrageous.

The question is, why did she blow up such a promising career? Can it recover? And, as the bitter stoush over the CFA threatens to tear the government apart, what happens next?

With Garrett under fire from within, and the government bleeding externally, all sides concede it can't go on like this, not unless they plan to follow in the footsteps of the Rudd/Gillard years. A truce of sorts is underway, but insiders say the path to salvation will require Garrett to bunker down for the next two years, support the government and defend her marginal seat from the threat of the Greens.

Garrett doesn't disagree. "My focus is on looking after the Brunswick community and working hard to ensure the re-election of the Andrews Labor government," she told The Sunday Age this week. Some, however, remain unconvinced.

Depending on who you talk to, Garrett is either a woman who fell on her sword out of principle, a scheming Lady Macbeth-type character intent on destroying the government, or something in between.

The first view holds that she refused to yield to a bully and to accept an industrial agreement she felt would undermine CFA volunteers, particularly through a clause that would give the union power to challenge (and potentially block) management decisions.

The second holds that Garrett had been intent on undermining Andrews, working in cahoots with the government's enemies and refusing to find a way forward with the United Firefighters Union.

As one senior Labor MP put it: "The great problem the government has confronted for the past six months is that we've had a minister who chose … to monumentally erode cabinet solidarity and chose to run an agenda that was basically a gift to the opposition."

The third, more nuanced position, is that Garrett made some poor decisions, perhaps blinded by anger over her treatment from Marshall and to some extent Andrews, who sidelined her in April when he met privately with the union boss and subsequently agreed to the UFU's demands.

To some, her angst was understandable. While Marshall and Garrett used to get along, the seeds of animosity were sown early last year, when Garrett refused to intervene in the disciplining of a senior MFB officer charged with distributing porn on his work computer.

Marshall declared war and, as EBA negotiations intensified, things went from bad to worse. Abusive firefighters trolled her on Twitter. A group of aggressive unionists harassed her at a media event aimed at encouraging women to join the fire services.

There were abrasive text messages, intimidating meetings, even an alleged threat by Marshall to put an axe through her head. At one point his behaviour reportedly got so bad that Garrett had to ask one of Andrews' advisers to stop him harassing her when she was on holiday with her three children.

In the meantime, Andrews was getting fed up. He believed his MP had become captured by the CFA board, and was allowing her personality clash with Marshall to get in the way of resolving the three-year dispute.

Garrett's factional patron Senator Kim Carr and other Left figures worked on an arrangement that would have allowed her to back down with dignity, but she couldn't bring herself to rubber stamp an EBA she didn't support. What's more, she had legal advice suggesting she didn't have the power to compel the CFA to sign the agreement, and would have to sack them if they didn't comply.

On June 10, Garret told Andrews she'd quit cabinet, minutes before it met to endorse the deal.

Since then, Garrett's life has been a study in contrasts. In the aftermath of last week's caucus meeting, about two dozen bunches of flowers were sent to her electorate office, which also received about 600 emails of support from the community.

A ReachTEL poll conducted by Fairfax Media also provided an interesting result: 35.9 per cent of voters said Garrett would make a better leader of the party than Andrews, who polled at 42 per cent.

Within Labor circles, it's a different story. Most of Garrett's colleagues are outraged, convinced she is the reason for the government's woes. Some are fuelled by revelations the CFA engaged a union-busting law firm under her watch; others point to the text message, inadvertently sent by her staffer to a government adviser with the same surname as the Herald Sun journalist for which it was intended, as evidence of betrayal.

Even her biggest power blocks within the union movement – the CFMEU (state secretary John Setka's wife Emma Walters is a close friend) and the Rail Tram and Bus Union (headed by another ally, Luba Grigorvitch) – have been noticeably quiet about the caucus ructions.

It's been a difficult fall from grace for a woman who has long been on an upward trajectory. The daughter of a Baptist minister, Garrett cut her teeth practising industrial relations and discrimination law at legal firm Slater & Gordon, worked as a political adviser to former premier Steve Bracks, and was elected to the inner-city Yarra Council in 2008, where she also served a stint as mayor.

She entered Spring Street in 2010, impressing people with a string of quiet but significant achievements: drafting laws giving donor-conceived people the right to know their identity, becoming the vice president of the federal ALP, co-authoring Labor's review into the Rudd government's 2013 election loss, which concluded, somewhat tellingly, that "the single biggest reason voters turned away from Labor was internal party disunity".

In person, the 43-year-old is engaging, smart and a strong media performer, assets that have helped fend off the Greens in her inner-city seat for the past two elections. But therein lies her enemies' conundrum: at the last state poll in 2014, the Greens' primary vote outstripped Labor's – 40 to 38 per cent – but Garrett eventually won after the distribution of preferences. Now, with a much higher profile and strong public support, strategists say she's probably the government's best chance of defending the electorate.

There is a view that Garrett can make a comeback – stranger things have happened in politics – but insiders say her "rehabilitation" will rely on being part of the team, and on all sides putting aside their grievances.

In recent days, she has ramped up her electorate outings, revived her Facebook page to keep locals up to date, but has otherwise kept a low profile in the mainstream media and corridors of Parliament. Perhaps it's a turning point.

The government, and the Labor Party more broadly, can only hope the wound has now been cauterised. "We simply can't allow this to go on, says Senator Kim Carr. "All disputes come to an end no matter how intractable. Our focus now has to be on the re-election of Daniel Andrews and his government and Bill Shorten as Labor prime minister."