ONE of the hallmarks of Alex Salmond’s two decades in charge of the SNP was his ability to encourage talented younger members.

Justice Secretary Humza Yousaf, former SNP Westminster leader Angus Robertson, advocate Duncan Hamilton and lobbyist Andrew Wilson, were all Salmond proteges who have made their mark in public life.

But Nicola Sturgeon, who has known Salmond for nearly thirty years, was always her mentor’s preferred successor. Both shared the same social democratic ethos and belief in making gradual steps towards independence. Even the dramatic events in 2004, when Salmond elbowed her out of the way so that he could regain the SNP leadership, worked to her advantage.

Salmond’s decision to upstage Sturgeon back then helped her enormously. She gained invaluable experience as his party deputy for ten years and as his number two in Government. By the time Salmond quit in 2014, she was the obvious choice to succeed him.

CATCH UP: Criminal investigation into leaks in Salmond sexual harassment probe

That close relationship is now dead, killed by a botched Government investigation into claims Salmond sexually harassed female civil servants. Last week’s hearing at the Court of Session, where the Government probe was declared illegal, have fractured the SNP in a way that never seemed possible.

Salmond’s allies believe Government figures, through leaks of damaging allegations, tried to wound him. Others are of the view Salmond is a bitter man who won’t rest until he has answers and scalps.

One thing can be said without hesitation. Salmond’s court victory was not a judgement on the allegations he faces. Police Scotland will investigate the claims against him. The women who made the complaints were let down by the Government, but it is hard to imagine detectives doing anything other than a rigorous job.

It is equally true that Sturgeon’s leadership is more vulnerable than at any point since she took over. Four years ago she was the “rock star” leader who addressed 12,000 party supporters at the Glasgow Hydro. It is not inconceivable, one of her backers told me last week, that she could now be forced out of office.

Consider the different strands of this scandal. The flawed Government probe, based on the investigating officer having prior contact with the complainants, does not jeopardise her leadership. It raises serious questions about the competence of the Government, but not for her personally.

However, her inexplicable decision to meet Salmond on multiple occasions during a live misconduct probe is an iceberg that is moving into view. Her decision will likely be poured over by various inquiries, followed by evidence sessions and the drip-drip of who said what at the so-called “party” summits at her house. Expect this to drag on for months.

And then there is the aspect that really winds up Salmond. Who leaked details of the Government probe to the Daily Record in August? On the day in question, the Government wanted to make an announcement on the internal investigation but Salmond, who denies the allegations, was unenthusiastic. His supporters saw subsequent leaks as a malicious attempt to destroy his reputation and they are determined to uncover the mole.

It is not hard to imagine how a parliamentary inquiry might handle this toxic element of the story. Any Government official called to give evidence could be asked: did you speak to the Daily Record on the day the article was published online? Any confirmation that a Government staffer even confirmed details of the case would be a nightmare for Sturgeon.

The wider issue is where power lies in the independence movement. Salmond was rightly criticised for asking ordinary folk to make donations to his legal fees, but it was telling that so many Yessers dug deep for him within 24 hours. It is difficult to think of many politicians who command such loyalty.

And look at the SNP heavyweights who have intervened since August. Noel Dolan, who is not believed to be the biggest fan of Salmond’s political style, said he expected the former First Minister to be “cleared” and criticised the Government's top civil servant Leslie Evans. Dolan was easily Sturgeon’s closest adviser in Government until he retired.

Tricia Marwick, a key adviser for Sturgeon during her aborted leadership bid in 2004, accompanied Salmond to court last week. Kenny MacAskill, who was going to be Sturgeon’s running mate before she pulled out of the contest fourteen years ago, was also by the former First Minister’s side. Salmond’s support within the party runs deeper than acolytes and helpers.

The rift also pre-dates the Government probe into Salmond’s alleged conduct and includes dissatisfaction with Sturgeon’s performance as First Minister. Some of his backers believe she lacks vision, has poor links with the business community, and are frustrated by her cautious approach to a second independence referendum. They feel he could do better.

There are already mutterings about a Salmond comeback, subject to him being readmitted to the party. One source said he could contest the nomination for the Holyrood seat in Aberdeenshire East, currently held by Nationalist Gillian Martin. Another insider said the seat in Aberdeen Donside, currently held by independent MSP Mark McDonald, would need an SNP candidate in two years. MP Joanna Cherry last week “liked” a tweet which called for him to be “back at the helm” of the SNP.

Meanwhile, given the daily horror stories about the state of public services, Sturgeon can hardly fall back on her domestic policy record. The First Minister said in November the strategy for securing another referendum might be to win the next Holyrood election. The question is whether she will be in post to make that case.