We need to talk about Schengen. We need to talk about free movement. We need to talk about the single market, customs union, and the European Court of Justice. We need to think about the whole EU package as it is now integral to the founding goal and electoral fortunes of Scotland’s governing party.

Europe matters to the SNP in a way it never has before. It is actively hurting it. Before the Scottish and EU referendums, Nicola Sturgeon’s affinity for Brussels was uncontroversial. When Europe was raised during the 2014 referendum, it was not the SNP’s support of the EU which was criticised, but its happy-go-lucky ideas for an independent Scotland staying in the continental Union after it had left the domestic one. Alex Salmond wanted a raft of treaties rewritten to let Scotland glide in rather than dally on the doorstep as a new applicant.

At the time, the SNP’s opponents, who were generally just as Europhile, were not querying the party’s overarching intent, but the membership terms an independent Scotland would face. These would inevitably be worse than those enjoyed by the UK, so why take the risk, went the refrain. The lack of detail and over-optimism were also cited as more evidence of the SNP’s naiveté / readiness to say anything to win.

That was then. Since the EU referendum, these abstract points have hardened into a sharp pain for the Nationalists. Last week’s British Election Study set out the facts. In the 2015 election, people who had voted Yes for independence voted overwhelmingly for the SNP. But in the 2017 election, not only was Nicola Sturgeon’s plan for a second independence referendum hurting her party, so too was her staunch defence of all things Remain.

Four in ten SNP voters who were Yes in 2014 and Leave in 2016 switched to Labour and the Tories. But there was no compensating gain for the SNP from the No/Remain camp. Despite the Tories backing a vigorous Brexit, a large number of No/Remainers turned to Ruth Davidson’s party, their support for the Union trumping that for the EU. The unforeseen resurrection of Scottish Labour thanks to Jeremy Corbyn added to the squeeze on the Nats.

The upshot was the SNP’s worst election reverse since 1979: the party lost 21 seats from its 2015 high, its vote share falling from 50 to 36.9 per cent. In response, the First Minister shelved her planned referendum bill until at least autumn 2018, meaning legislation will not be ready before Brexit in March 2019, and Scotland will leave the EU as part of the UK. But Ms Sturgeon did not abandon a referendum altogether, and said one was still “likely” before the 2021 Holyrood election, when her “triple-lock” mandate runs out.

But if she ever gets the power to hold that referendum - and that would probably require an early change of UK government - she still faces a massive challenge. The baseline for Yes is no longer the 45 per cent of 2014, but closer to the SNP’s 37 per cent in June, that part of the Venn diagram where backing independence and the EU reliably overlap. Not much. If the SNP holds another referendum saying independence means EU membership it will probably do worse than in 2014, crippling the party and Yes movement for a generation. But given Ms Sturgeon’s referendum mandate is based on Brexit dragging an unwilling Scotland out the EU, what else can she do?

The way out of the bind, one member of the government suggested to me this week, is to “de-couple” the issues. Instead of a single referendum question on independence, the ballot paper would pose two. The first would ask if Scotland should be independent, the second if an independent Scotland should rejoin to the EU. The SNP would advocate Yes-Yes, but Yes-No votes would still help deliver independence. “There’s a lot of chatter in the party about it,” my source said. “I could easily get behind it at the party conference in October.”

There’s an obvious precedent for such a vote - the devolution referendum of 1997, with its first question about a Scottish Parliament and its second about whether such a parliament should have tax-varying powers. The first was carried 74:26, the second 60:40.

A similar referendum involving independence would be harsh test of which union people prioritised, the UK or the EU. Many Yes/Leavers might vote No to independence to safeguard Brexit. It would mean huge headaches for the SNP, such as setting out twin scenarios for independence, one for life in the EU and one for out. But those are matters for another day. For now, and with conference season obliging Ms Sturgeon to say something hopeful on the issue, some of her MSPs hope she will start to get creative.