When Nicola Sturgeon addressed a private gathering of Scottish National party politicians at Edinburgh Napier University towards the end of August 2018 and little more than a week after the original sexual harassment allegations against her predecessor Alex Salmond were made public, she spoke frankly: “How we deal with this and how we are seen to respond to this will say a lot about who we are as a party and also about the country we are today and want to build for the future.”

Speaking outside the high court in Edinburgh on Monday afternoon following his acquittal on 13 charges of sexual assault, Alex Salmond suggested that the verdicts would ultimately say something very different about the SNP. He referred to “certain evidence I would like to have seen led in this trial”, which would now “see the light of day”. Sources close to the former first minister were already briefing his belief that Nicola Sturgeon herself played a role.

As Salmond’s supporters welcomed the verdicts, calling variously for unnamed heads to roll and an independent inquiry into the SNP’s handling of complaints, and the Scottish Conservative opposition at Holyrood described “a national political scandal with profound questions of integrity for the first minister and her SNP government”, it was clear that when the coronavirus pandemic has abated the issue will return to the top of the political agenda. The verdict brought the most significant case in Scottish legal history to an end – but it also marked a new chapter in a fight that could tear the party leadership apart.

A key Salmond ally, Joanna Cherry, the prominent MP who last year garnered plaudits for leading the successful legal challenge to the prorogation of parliament, said that Salmond should be allowed to rejoin the SNP “without delay” after his resignation in August 2018 to avoid causing “substantial internal division” as he put it at the time.

As he resigned, the former SNP leader announced that he had set up a crowdfunder to support his judicial review of the Scottish government’s handling of the allegations. He attracted more than double the initial target within three days after more than 4,100 individuals donated a total of £100,000, underlining the loyalty that Salmond continued to command among senior figures and also rank and file independence supporters.

It is often said that the SNP is a party like no other; that it is configured more like a family, led by a tight-knit group who have kept faith together across decades of public derision and unpopularity. Their loyalties were forged in opposition long before the party became the electoral force it is now. There have been some spectacular internal disagreements – changing policy on Nato membership in 2012, for example – and personality clashes. But these have always been eclipsed by the overarching project of independence for Scotland and a pragmatic recognition of the discipline and unity required to achieve that.

Facebook Twitter Pinterest Alex Salmond with Nicola Sturgeon in 2007. Photograph: Murdo MacLeod/The Guardian

At the heart of the SNP family was the relationship between Sturgeon and her “friend and mentor”, as she so often described him, Salmond. He once described it as an “unstoppable partnership”. It now lies fractured beyond repair. By Sturgeon’s own admission, the pair have not spoken since July 2018. Strain and distress were etched on her face as she responded to the reports of Salmond’s arrest in January 2019. In the same month, Salmond accused Sturgeon of “rewriting history” after his pivotal role in the rise of the SNP was excised from the party website.

Older activists in particular reflect Salmond’s furious sense of betrayal that Sturgeon’s code of conduct for the Scottish government introduced in 2017 applied retrospectively to former ministers. It was as though the new code was designed to catch him out, some believed.

In court, Salmond set out his own firm conviction that witness A, a senior Scottish government official, had orchestrated the charges, encouraging a number of other women to make claims against him that they would not previously have done.

Much of the Salmond camp’s criticism is also directed at Leslie Evans, Scotland’s chief civil servant who drafted the code with Sturgeon, and her oversight of the initial sexual harassment investigation, which the Scottish government was forced to concede was “tainted by apparent bias”, and whose role cannot escape tough scrutiny in the forthcoming parliamentary inquiry.

There is also a significant intersection between those who have spoken publicly in support of Salmond, those who are critical of what they consider to be an overly cautious strategy on independence, and those who have concerns about the Scottish government’s plans for transgender legal reform.

The forthcoming contest for the Edinburgh Central seat between two of the SNP’s most influential figures lays the divisions bare. Joanna Cherry is campaigning for the Holyrood seat, as is the SNP’s former Westminster leader and Sturgeon supporter Angus Robertson.

Robertson is known to favour a more gradualist approach to independence, while Cherry wants to test Holyrood’s power to hold a second referendum in the courts, and has meanwhile faced social media abuse for her opposition to SNP plans to bring in self-identification for gender recognition certificates, which resulted in a reported showdown between her and fellow MP Mhairi Black at a recent Westminster group meeting.

But there are many who dispute that the rift between Salmond and Sturgeon translates into an irreparable split in the party itself, arguing that this fundamentally misunderstands how the ground has shifted since #MeToo, especially for the tens of thousands of SNP members who joined after the first independence referendum, just as Salmond stood down as first minister. Their ambitions for independence, often strongly feminist and focused on equality, became ambitions for their adopted party, with many more women and LGBTQ+ activists becoming involved and demanding the SNP share their values.

Salmond’s behaviour once free from the restraints of office – bombastic pronouncements on independence, sexist jokes at the Edinburgh fringe and his long-running show for Kremlin-backed Russian broadcaster RT – likewise perplexed the expanded, modernised party. While it is impossible to overestimate Salmond’s impact on the Scottish independence movement, among many younger activists surveyed by the Guardian, their view of Salmond – brutal as it may be – is as a historical figure, “yesterday’s man”, and “irrelevant”.

Observers noted that since her election in November 2014, Nicola Sturgeon has been an unapologetically feminist leader, immediately appointing a gender-balanced cabinet and ushering in a significant change in style and policy. In 2015, she presided over the election of a new cohort of SNP MPs, many of them yes movement mavericks whose interpretation of party loyalty has been radically different from previous incumbents, and in 2016 the SNP group saw a gender and generational shift at the Holyrood elections.

But the response to Salmond’s crowdfunder appalled many independence-supporting women, who feared it would deter others from coming forward and that the case could become a lightning rod for existing sexism within the yes movement. Many anticipated the trial with dread, concerned that the proceedings would be politicised to the extent that the voices of the women involved would be drowned out. Following the verdicts, younger female activists tweeted their “disgust” at those seeking to make political capital from the outcome.

On the evening of the verdicts, the Twitter hashtag #ibelieveher was trending as Scottish Rape Crisis revealed a spike in calls to its helpline, prompted by the detailed reporting of the trial. Worries about in-fighting after the trial leaving activists disillusioned and demotivated are now academic since Sturgeon herself suspended independence campaigning and urged activists to focus on helping their communities through the pandemic.

Party insiders have always been realistic about the difficulties of moving cleanly on from the case with a parliamentary inquiry to come. But such a resounding acquittal for Salmond, and his immediate threat to release more evidence about the involvement of the Sturgeon government’s staff and senior officials in both the initial investigation and subsequent police inquiry, make the coming months all the more dangerous for her government.

When the criminal charges were first brought against Salmond, his anger had a ferocity that Sturgeon reportedly was unprepared for. Now some close to Salmond suggest that his sense of betrayal and desire for revenge will now have reached epic proportions.

Many have praised Sturgeon’s steadfast and humane leadership thus far through the national health crisis, but it is her predecessor who may yet signify her greatest challenge in the months to come.