London: The perceived wisdom in much of the UK ahead of Thursday’s European Union referendum vote is that Scottish Nationalist dreams of independence would be reawakened should Britain opt for a Brexit.

Former Prime Minister Sir John Major has gone so far as warning that a victory for Leave could ‘tear the UK apart’ as the pro-European Scots would be outraged at being dragged out of the bloc by their neighbours.

But the prospects of a second bid for independence — the first in 2014 saw 55 per cent of the Scottish voters choosing to stay within the United Kingdom — on the back of a Brexit are not as clear cut as that.

First Minister Nicola Sturgeon has repeatedly said a material change in circumstances, such as being taken out of the EU, could trigger a new referendum, but it is also clear the Scottish National Party (SNP) leader would only take the plunge if there was a significant surge in public support for independence — the polls would need to be at least 60-40 in favour.

With support currently standing at just below 50 per cent, John Curtice, professor of politics at the University of Strathclyde and writer of the What Scotland Thinks blog, is pessimistic a Brexit would create a large enough swing for Sturgeon to act immediately.

“There would probably be evidence of a small swing to independence, but not necessarily enough for Nicola Sturgeon to call for a referendum,” Curtice told Gulf News. “Polls have found that rather more say they will vote yes [on independence] if the UK votes to leave the EU than say they would do so if there were an independence referendum now.

“But the swing in these circumstances is not a large one — between 3 and 6 points. Applying that swing to the average level of support for independence in all polls conducted this year suggests that a UK-wide vote to leave the EU might just result in majority support for independence — but only just. At 51 or 52 per cent, it would certainly fall well short of the 60 per cent figure.”

Even if there was a significant post-Brexit shift in public opinion, there are other hurdles to overcome before a second referendum can be called.

The legal authority for the Scottish Parliament to hold an independence vote expired at the end of 2014 and only Westminster has the power to change that.

If MPs in London weren’t in favour then the SNP could force through a protest vote at Holyrood, but that would lead to complicated legal wranglings and, as Curtice points out “the SNP no longer has a majority in the Scottish Parliament. They would need the Greens on board and, while they are in favour, they are not necessarily desperate to make it happen by the day after tomorrow.”

The writer is a freelance journalist based in the UK