ew spectacles are more horribly watchable than a political feud. From Caesar and Pompey in the ancient world to Gordon Brown versus Tony Blair in the modern one, feuds are riveting and often barely believable in their intensity. During the Napoleonic wars, a pair of cabinet ministers even found time to fight a duel, in which the foreign secretary George Canning was shot in the thigh by the war minister Viscount Castlereagh. The feud between Alex Salmond and Nicola Sturgeon can now be added to the list. That the former Scottish National party leader and first minister is out to bring his longtime protege and successor down may seem like the stuff of an overwritten melodrama. But it is also true – and increasingly serious. Larger issues hang on the outcome, above all the SNP’s future electoral clout and Sturgeon’s chances of achieving Scotland’s independence from the United Kingdom. At the root of the bitterness is Salmond’s claim about the role he says Sturgeon and her team played in the charges of sexual misconduct against him that surfaced in 2018. These charges eventually came to court, where Salmond was cleared on 13 counts by an Edinburgh high court jury in 2020. Ever since, he has planned his revenge, but the personal issue is caught up in a complex web, especially over pro-independence tactics and the wider #MeToo movement, on both of which there are divides in the nationalist camp. From the start, Salmond alleged abuse of process against Sturgeon’s team. He won a separate court case on this issue in 2019. That led to two current inquiries. The first is by the former Irish director of prosecutions James Hamilton, into whether Sturgeon broke the ministerial code; if Hamilton finds against her, she may be forced to resign. The second, by a special committee of the Holyrood parliament, is a wider examination of the Scottish government’s handling of the case. This week, Salmond sent an explosive 26-page document to the Holyrood committee. It alleged “a deliberate, prolonged, malicious and concerted effort amongst a range of individuals within the Scottish government and the SNP to damage my reputation, even to the extent of having me imprisoned”. Salmond’s evidence session is on hold because of legal disputes. It may take place on Friday. In any event, Sturgeon emphatically rejects his allegations. Her supporters were reported this week to think Salmond has now “gone the full Donald Trump”. The SNP has certainly always had its cult-like qualities. Public argument is almost as rare in the SNP as it is in Sinn Féin. But the familiar internal discipline has been breaking down. The high profile Salmond supporter Joanna Cherry has been sacked from her frontbench role. Jockeying for Holyrood nominations has been ruthlessly factional. Salmond’s pushback against the SNP’s chief executive, Peter Murrell, who is married to Sturgeon, has wider sympathy. But it is a very high risk venture. Support for Salmond’s approach among the SNP’s younger members is thin. Only 14% of SNP voters think he has generally told the truth in the dispute with Sturgeon. Some see him as a political suicide-bomber attacking the cause. The affair offers ridicule or infamy, even if he gets his pound of flesh. But by hammering away at the SNP’s centralism and loyalism, Salmond is landing damaging blows. Thus far, Salmond’s efforts have not significantly hurt the SNP’s standing. Support for independence still commands a majority, though there was a dip last week. The number of Scots who think Sturgeon has been telling the truth in her argument with her predecessor is higher than Salmond’s figure of 13% – yet it is only 30%. Most people don’t know or don’t care much. Right now, most are more concerned about Covid than the SNP’s divisions. Nevertheless the political clock is ticking and this could change. The committee is under pressure to report before Holyrood dissolves for campaigning ahead of the 6 May Scottish parliament election. Meanwhile, the Hamilton report is expected in mid-March. The destructive potential of the issues should not be underestimated. If Salmond succeeds in ousting Sturgeon, or even if he damages her badly – which he may, whether he ousts her or not – the political consequences will still be big. Scotland goes to the polls in 10 weeks’ time for an election in which calls for a referendum on leaving the UK will be front and centre of the SNP campaign. With Sturgeon already riding high in the polls for her handling of the Covid pandemic, and support for independence continuing to run strongly, a convincing SNP victory has long been baked into political planning in both Edinburgh and London. Covid is the dominant political issue of the day in Scotland, just as it is everywhere, but the SNP is not governing Scotland as well as it pretends. It has been in power for 14 years now, and it certainly shows. If the feud becomes an SNP civil war – and there are signs that it may – the electoral damage could be more rapid than some suppose. Only a small slippage of support for the SNP would change the political landscape significantly. That possibility should neither be exaggerated nor oversimplified. It remains a long-shot outcome. The SNP’s rivals would be mistaken to allow their hostility to colour their judgment on how things may turn out. Nevertheless, it is now not a complete fantasy that modern Scottish party politics may be heading in a less predictable direction. For one thing, the nature of the mandate the SNP is able to claim in May is not easy to predict. Several things may change soon. Sturgeon’s daily command of Scotland’s TV screens may be reduced to allow fairer access for opposition parties. Large amounts of postal voting will have an effect, but in what direction? Turnout for the last Holyrood elections was 56%. If that drops by a few points – and in the recent Catalan elections turnout fell by a third – it will be harder to claim a mandate for a second referendum. One of Scotland’s leading authorities on the SNP, Prof James Mitchell of Edinburgh University, said this week that the party’s divisions were such that it needed time in opposition “to sort itself out”. Such bloodletting, he said, normally follows an electoral defeat rather than preceding it. The party had “no credible strategy to deliver a referendum” and had weakened its own case by “intoxicated spin” and “empty rhetoric”. Such warnings from someone who is not an enemy of the nationalist cause deserve to be taken seriously. It remains unlikely that the nationalists will in fact snatch defeat from the jaws of victory. But it cannot be ruled out. Martin Kettle is a Guardian columnist