Here’s an opening sentence that will surprise a lot of people: the SNP is right about Brexit. Right that last year’s referendum was badly executed, right that the Leave campaign traded in blatant mistruths, right that the negotiations have been shambolic and right that the stated objectives are unrealistic.

And right about the Single Market. The Scottish Government – and its expert panel of advisers – deserves credit for having first identified the only logical compromise between Remain and Leave, for the UK (as a whole) to stay part of the Customs Union and Single Market, mostly likely via the European Economic Area (EEA) or European Free Trade Association (EFTA).

Yesterday, Labour finally caught up with Keir Starmer confirming that a Labour government “would seek a transitional deal that maintains the same basic terms that we currently enjoy with the EU”, ie membership of the Customs Union and Single Market and therefore abiding “by the common rules of both” for a four-year period.

There’s a lot of ferocious circle squaring going on: both main parties want a hard Brexit (just not yet), but realise the UK crashing out of the EU in 2019 would constitute economic self-harm of the highest order. Thus, the emerging consensus in favour of a transitional period.

But in spite of my opening paragraphs, the SNP has its own circles to square, for while it has consistently held the line on membership of the Single Market, it still hasn’t found a way of reconciling that with its long-standing aim of “independence in Europe”. Being part of the EEA or EFTA is all well and good, but it’s not the same as full EU membership.

In the run up to June’s general election, it attempted to finesse its position, talking of its own “transitional” arrangement whereby that half-way house might lead to rejoining the EU. Now given there’s no reason an independent Scotland wouldn’t immediately reapply (indeed the mood music from the Continent made such a route more likely than ever before), this can only have been contrived to keep hold of SNP voters who disliked Brussels almost as much as London.

As the election result made clear, it didn’t work: Yes-Leavers deserted the SNP because of its perceived enthusiasm for the EU, while some No voters, toying with the idea of shifting to Yes for the same reason, ended up wary about perceived backsliding.

Since polling day, therefore, the SNP has gone silent on its long-term plans for EU membership. No more talk of the EEA or EFTA and instead calling, as Stephen Gethins did yesterday, for “continued membership of the European Single Market, period”, mainly to ensure the Scottish economy doesn’t “suffer the harmful, chaotic effects of being isolated from the world’s largest trading bloc”.

That qualification – one might call it “scaremongering” – highlights another circle the SNP hasn’t yet squared. Yes, the party has by and large been correct about Brexit, but here’s the rub: you cannot credibly warn against the “chaotic” effects of departing from one political union while proposing to leave another; you cannot dismiss Brexiters’ faith in achieving three impossible things before breakfast while maintaining that, in the case of Scottish independence, similarly impossible things are eminently achievable.

At this point certain readers will summon up the usual straw men in their defence. Ah, they’ll say, but the EU and UK are different sorts of union. That, of course, is true, only no-one suggests otherwise, just that the arguments against leaving one are remarkably similar to those against leaving the other. And it’s that Orwellian contortion that undermines the central thrust of the SNP’s otherwise sensible position on Europe.

Take last week’s GERS figures, which once again highlighted that while the UK is a net contributor to the EU (although that doesn’t mean there won’t be a bill for leaving), Scotland is a considerable net beneficiary from the UK. So, to maintain, as many do, that leaving the EU will be economically damaging but that leaving the UK will magically plug a £13bn gap is, to put it mildly, heroic.

In response, further straw men are erected. Ah, say believers, GERS tells us little about what an independent Scotland would look like. Again, this is (sort of) true, but no-one really argues that it does, merely that it implies the starting point for an independent Scotland would be, again to put it mildly, challenging.

Thus, the Scottish Government’s usual mantra that with control of all economic “levers” it would be better placed to “grow the economy” is strikingly inadequate. The SNP is rightly scathing of Brexiter optimism about mitigating any post-2019 damage to the UK’s economy via quixotic trade deals, yet when it comes to independence it indulges in similarly breezy optimism.

Don’t worry, they both say, trust us: it’ll be all right on the night. Well, surely what the Brexit shambles demonstrates is that one should never trust the optimists. In fact, it was the so-called “scaremongerers” who were closer to the mark in terms of what might happen if there was a Leave vote; “Project Fear” might have been negative and a little over-the-top, but it’s also proving correct.

No surprise then, that there’s talk in the Nationalist camp of decoupling independence from Brexit. Last week the SNP MP Tommy Shephard restated his support for the EU but said it “could be better” and urged his party to develop “a critical narrative” about how the EU ought to develop. More to the point, the negotiating stance of an independent Scotland ought not to be “membership at all costs”, while any deal should be “put to the people of Scotland for confirmation in a further referendum”.

For what it’s worth, I also reckon the SNP should back calls for a second referendum on Brexit, which it’s been noticeably reluctant to do for fear of creating a precedent which might later apply in Scotland. But looked at from another direction, wouldn’t such a volte face be worth it? By conceding a second ballot lest independence end up like Brexit, they’d probably increase the chances of an initial Yes vote, and that, after all, would be half the battle. There are, in other words, several more Nationalist circles to be squared.