Nicola Sturgeon has said a vote to leave the European Union against the will of the people of Scotland would “almost certainly” fuel support for another independence referendum.
People in Scotland who want to Remain in the EU outnumber Leave by around two to one, in contrast to the rest of the UK where Remain is only slightly ahead, according to the polls.
However, with around a tenth of the UK population, the entire weight of the Scottish electorate will not be enough to out-vote Eurosceptics if Leave wins in England on June 23.
This is the political storm that could drag the UK out of Europe and push Scotland out of the UK, according to the SNP. Ms Sturgeon has said this is not the outcome she desires, insisting she would prefer an independent Scotland side-by-side with its closest neighbour in Europe.
But her political opponents who share her enthusiasm for the EU have accused her of speculating on defeat with her repeated warnings of another independence referendum. Ms Sturgeon has never pointedly proposed another referendum, but merely warned that Brexit would lead to an “inescapable” shift in public opinion.
An Ipsos Mori poll in February found 54% of Scots would vote Yes after a Brexit, with No falling to 39%.
Once undecided voters are removed, this would put the SNP within touching distance of the 60% support it is reportedly seeking before it risks another referendum.
But it is unclear how the polls would move once the implications of a Brexit sink in.
The debate in Ireland shows the potential problems Scotland could face if it leaves the UK to remain in the EU, with warnings of trade barriers and border patrols.
It remains to be seen how the SNP will manage demand for a second independence referendum from its nationalist grassroots in the forthcoming Holyrood election.
With Scotland going to the polls on May 5, the Brexit-IndyRef storm will feature prominently in the SNP’s spring conference next week. But with many commentators warning that a second No vote would sound the death knell for Scottish independence, the SNP will tread carefully whatever the outcomes on May 5 and June 23.