Theresa May’s admission last week that the United Kingdom will have to leave the single market at the same time as it leaves the EU means the Scottish nationalists face a difficult choice: relent or demand a second independence referendum.

Nicola Sturgeon, the Scottish National Party leader and regional first minister, had urged “flexibility” in Britain’s exit negotiations with the EU. 62 percent of Scots voted to remain in the bloc last summer against 47 percent of the English. Many feel like Sturgeon that Scotland is being taken out of the EU against its will.

Sturgeon warned that a “hard” exit, under which all parts of the United Kingdom would lose access to the European single market, could convince her party to seek independence a second time.

Scots unsure

The nationalists lost the first independence referendum, in 2014, when 55 percent of Scots decided against breaking away.

Some surveys taken since the EU referendum suggest a plurality of Scots, if not a majority, might now vote to secede after all.

But the numbers have fluctuated and the polls consistently show that one in ten Scots are unsure what to do.

That means Sturgeon can’t be sure she would win a second referendum. And losing a second time in a row would surely set back the nationalist cause for decades.

Things can always get worse

The best thing Sturgeon can do is probably wait for events to play out in her favor.

The main argument from the unionists has always been that Scotland’s economy is more dependent on the rest of the United Kingdom than it is on Europe.

Recent conditions bear that out. Falling oil prices have pushed up the regional deficit, belying the SNP’s rosy predictions of a petroleum-fueled future outside the kingdom.

But if Brexit goes badly and the Scottish economy suffers (more) as a result, the mood could shift in favor of independence and rejoining the EU.