CLAYTON Christensen once said: “You may hate gravity, but gravity doesn’t care.” Mr Christensen was a business consultant, but his insight constitutes sound advice in the world of politics, too.

The Tory Party is more than 30 points behind in polling for the next Westminster election and it is, of course, in vogue to blame that on Liz Truss and Kwasi Kwarteng. That’s not the wrong analysis, as such, but it is incomplete, because the main blame actually lies with political gravity.

Long-term governments and economic crises are a toxic mix. John Major engineered a solid economic recovery from the Exchange Rate Mechanism crisis, but it mattered not. Gravity won. Gordon Brown led the global response to the financial crisis, but gravity did not give him the credit.

Political gravity had a grip on this Tory Government before Ms Truss started running it.

But does this basic political rule apply in Scotland? The SNP has been in power in Scotland since 2007, and it is by no means clear if and when that rule will see its end.

There are good reasons for this. One is the lack of a credible opposition. A more prominent one is the overlaying of constitutional politics onto our elections. However, as the SNP gathers for its annual conference in Aberdeen tomorrow, its leaders would be justified in reflecting that they have been the authors of their own dominance.

This is a government which, notwithstanding some recent missteps, has been exceptional both at governing and at increasing its own base since the day it entered office in May 2007. It has reached far outside the political bubble and implemented policies which have had a tangible impact on people's lives, and on their finances. And those policies have been ruthlessly targeted at people who have many decades of voting ahead of them.

The taxpayer-funded extension of nursery childcare, school meals and university tuition fees, as well as the baby box, have put a substantial proportion of disposable income back into the pockets of young families; in many cases more than could ever be achieved through a tax cut. Add to that a sharp focus on climate change, which targets that same demographic, and you have an entire generation of voters who have very, very good reasons to think highly of the SNP.

Moreover, this is not a government which has relied only on smart political strategy and targeting. It is a government populated by intelligent, pragmatic centrists, both elected and appointed as advisers, who have proven themselves to be more solid and dependable than their counterparts at Westminster.

However, for the first time since it entered government 15 years ago, the cloud of change lingers over this party, unsure whether to blow over or to burst into rain. In less than a week from now, the Supreme Court will adjudicate on whether or not the Scottish Government’s proposed October 2023 referendum can take place without the authority of Westminster. If, as everyone who opines on the matter seems to expect, the court declares that it cannot, it locks the SNP into treating the next General Election as a proxy independence referendum.

This will be Nicola Sturgeon – the safe, solid, incremental leader of nationalism – putting all her chips on black and rolling the dice. Ms Sturgeon has little choice.

The SNP’s message at the last five Scottish and UK elections has been the same – vote for us for Indyref 2 – however the absence of a government in London which is willing to grant a Section 30 order makes that message less and less credible. Ms Sturgeon is caught in a loop, and she needs to break it before her party loses patience. Were the SNP to win more than 50 per cent of the vote, which is not outwith the limits of possibility, the vote would not be treated as a legitimate mandate for independence, but it may be treated as a legitimate mandate for a second, real, referendum, particularly were Sir Keir Starmer to be Prime Minister.

That outcome would keep the train on the track, accelerating. The trouble is, though, that there is at least an equal chance that the day after the next General Election, the train will be derailed and upside down.

The SNP needs the General Election campaign in Scotland to be laser-focused on the proxy referendum. It must be a single-issue campaign: vote Yes by voting for the SNP (or the Greens) and vote No by crossing the box next to a Unionist party.

Ms Sturgeon cannot afford for other issues to bleed into the campaign, partly because it would delegitimise the proxy referendum nature of the vote, but also because in order to maximise her vote share she needs soft unionists to believe that their alternative to the Tories is an independent Scotland, not the Labour Party.

And, yet, were the election to be held tomorrow, it seems rather likely that voters would hold their pencil in their hand while thinking about interest rates and fuel prices, not about independence.

The capitulation of the Tories, and the elevation of Sir Keir Starmer, is catastrophic not just for the Tory Party, but also for the SNP. Liz Truss accidentally torpedoing the Scottish independence strategy. The very definition of irony.

There are no certainties here. Two years is an eternity in politics. Commentators like me, and the media, have a nasty habit of telling everyone precisely what is inevitable, only to be proved spectacularly wrong. We may see inflation considerably lower in two years than it is today. The pound may have strengthened. Fuel prices and interest rates may have stabilised. The economy may be growing. And, we must not forget, the column on the payslip which goes to the taxman will have a smaller number in it.

Counter-intuitively, that is what the SNP needs. Independence supporters need a re-strengthened Tory government. They need the economy off the table at this election. And the Tories back on it.

The SNP is a party which has created and deserved its success. But the SNP needs the rub of the green now. Because gravity doesn’t care.

• Andy Maciver is Founding Director of Message Matters and Zero Matters