The Scottish Government currently presents one of the most baffling – and for unionists, deeply frustrating – contradictions in British politics.

On the one hand, the SNP are defying in gravity. After 13 years in office – long enough to see off New Labour – they are still streets ahead in the polls, on course for a comfortable victory at next year’s Holyrood elections.

Even better (or worse), after years of waiting for a post-Brexit surge that never arrived the cause of their hearts, breaking up the UK, has finally managed to claw out a polling lead, the proposal lifted by the perception that Nicola Sturgeon has had a good pandemic and the anticipated unpopularity of Boris Johnson.

Whatever your opinion of the Nationalists or their project, this sort of longevity really is a remarkable achievement. Their administration is defying political gravity.

Yet it also really, really isn’t. Look up from the polls for a moment and the accumulated baggage of thirteen years in office – and longer still of eerie, phalanx-like internal discipline – are clearly taking their toll. The SNP is both assailed on multiple external fronts and wracked by deepening internal divisions.

Just this week, for example, the row over the ongoing inquiry into the Scottish Government’s botched investigation into allegations against Alex Salmond took another poisonous turn when the Holyrood committee conducting it claimed that its work was being deliberately obstructed by the administration. Oliver Mundell, a Tory MSP, was ejected from the Scottish Parliament after accusing the First Minister of ‘lying’ when she offered to give any investigation her full support.

Nor is this discontent confined to opposition MSPs. The SNP were criticised for stacking the committee chairs with Nationalists, but even Linda Fabiani, the convenor, has gone on record as saying that she and her colleagues have been “completely frustrated”. Today’s Guardian reports that MSPs have now appealed to the courts to try and break the deadlock.

The extremely tight senior leadership of the SNP, which was an asset to its command-and-control culture when things were good, now makes it difficult to deflect problems away from the top. Peter Murrell, Sturgeon’s husband and Chief Executive of the SNP, is now in the spotlight. Not only is he central to allegations that the SNP are obstructing the Holyrood probe, but he now faces claims that he tried to pressure the police to investigate Salmond.

Murrell himself is now firefighting on multiple fronts: not only is he in the sights of the other parties, but the anti-Sturgeon faction inside the Party is calling for his head. A move by grassroots activists to try to unseat him may be on the cards. The Nationalists’ internal divisions – which Stephen Daisley plots onto the two axes of Salmondite/Sturgeonista (on the practicalities of independence) and Woke/Sensible (on things like gender recognition) are heating up.

This surfeit of distractions perhaps helps to explain why it looks as if the SNP might be starting to lose their grip on the domestic agenda. An FoI request by the Tories has found Nationalist supporters very critical of the Party’s controversial Hate Crime Bill. One of Scotland’s richest businessmen (and second referendum supporter) has called on the Scottish Government to park the question of independence until the pandemic has passed, which will exacerbate tensions with the Salmondite ‘fundamentalist’ wing.

More seriously, a long-awaited report into the release of patients infected with Covid-19 into Scottish care homes – another issue in which the question of what Sturgeon knew and when is at the fore – has been delayed, again.

The abominable treatment of students at Scottish universities, which have seen thousands of young people essentially confined to quarters, is another story which might finally cut through the Nationalists’ seemingly bullet-proof reputation. The First Minister has defended the restrictions as “common sense”, but she has now been moved to apologise. Sturgeon is also coming under strong pressure to publish the scientific advice behind her lockdown decisions by local government leaders in Aberdeen, which was forced back into lockdown earlier, who are incensed at her apparent refusal to order the same for Glasgow (where her constituency is) despite apparently higher levels of Covid-19 transmission.

All of which makes it easy to see why the Government might be tempted by its stated strategy of simply refusing another referendum (even if they need to put more work into justifying it). With such strains on the SNP, and no obvious successor to Sturgeon of remotely the same calibre (and new electoral difficulties for the obvious contender), it might be that the question can be put off until time finally catches up with the Nationalists.

But the Tories’ own recent history should temper any optimism about that. One need only recall the way that Theresa May’s Government managed to lurch on, sometimes shedding a Cabinet minister a month, without the Conservative falling below 40 per cent in the polls to see how coalitions built around existential questions can prop up political vehicles which might fall to pieces in other circumstances.