MORE than two out of five Scots would accept a ‘hard' border with the rest of the UK if it meant staying in the EU.

An exclusive BMG poll for The Herald found that 43 per cent would accept Scotland remaining inside the EU even if this brought the kind of frontier controls at Gretna and Berwick which many experts dismiss as scare-mongering.

But it emerged 57 per cent would prefer Scotland to be outside the EU if that meant it could retain free trade and open borders with England, Wales and Northern Ireland.

The new figures came amid warnings from Europe that a hard Brexit - opposed by First Minister Nicola Sturgeon but the option Theresa May is facing pressure from within her party to deliver - would see Scotland stripped of key powers, such as those over farming, fishing and the environment.

In a potential blow to the entire Devolution settlement, experts believe the UK Government would have to prise back controls from Holyrood if it seeks a new "British single market" to replace the current European one.

Our poll also found that the Scottish public is torn over which of these two markets is most important: the EU or the UK.

Scots opted for both in roughly equal numbers, 39 per cent to 40 per cent.

Unionist politicians are increasingly presenting Scottish independence as a choice between England - by far this country's main trading partner - and the EU. However, economists have cautioned against relying on estimates suggesting that Scotland exports four times more to the UK than to the EU.

Professor David Bell of Stirling University said: "It is not good to see politicians bandying around slogans based on these numbers."

There is no official measure of goods crossing the English-Scottish border and, Prof Bell said, it would be "doubly difficult" to calculate exports and imports of services.

Last month a report by leading academics published by the Political Studies Association warned that "with Scotland in and the UK out of the EU, there would be a hard border between the two".

It suggested that there was no evidence that Scottish voters would be ready "to abandon the UK market in order to remain within the European one".

However, pollster Robert Struthers, from BMG Research, said: “An astonishing proportion of Scots would be comfortable with a hard border between the Scotland and the rest of the UK if it meant the country could stay within the EU. But these are disproportionately Yes voters, Remain voters and voters on higher incomes and occupational classes."

But Mr Struthers also warned that Ms Sturgeon was now heavily relying on the small group of voters who backed both Yes and Remain - just one quarter of the electorate.

"The EU referendum result presents a new divide in Scottish politics, of which the SNP are pushing for just one small part. The Yes-Remain group which accounts for around one quarter of voting Scots" he said.

He questioned whether the SNP was moving from being the party of the 45 per cent and "becoming the party of the 27 per cent" - representing those who identify as both 'Yes' and 'Remain' voters

Reacting to the poll, a Scottish Government spokesman said: “Brexit is by far the biggest threat to Scotland’s jobs, prosperity and economy, and that is why we have always been clear that staying in Europe – and maintaining membership of the world’s largest single market - is the best option for our future.”

Scottish Labour’s economy spokesman Jackie Baillie: "People in Scotland value being part of the UK and the economic benefits that brings, and that's why we voted decisively to remain in the UK just two years ago.”

Ross Greer MSP, the Scottish Greens’ external affairs spokesperson, said: “All sides are committed to avoiding a hard border between the North and Republic of Ireland so the chances of erecting one between Scotland and England – under any constitutional arrangement – seem pretty remote."

Meanwhile, writing in today's Herald, Scottish EU law expert, Alastair MacIver of Tilburg University in the Netherlands, warned that Holyrood could be the biggest loser from hard Brexit.

He said: "No UK single market currently exists and establishing an effective and lasting one would entail a large expansion of the reserved powers vested in Westminster.

"This would see Holyrood lose some of its current powers and miss out on those repatriated from Brussels."

Mr MacIver's warning contradicts claims from some on both sides of the independence debate that Brexit could lead to more Devolution. It also, he said, explains why Scottish Government is expected to argue at the UK Supreme Court for Holyrood to have a say on Brexit.

Mr MacIver said: "We underestimate at our peril the extent to which the devolution settlement of 1998 was premised on a European platform of rules followed by Westminster and Holyrood alike. Brexit upsets that assumption. This is precisely why many are urging consent from Holyrood."

BMG Research poll a representative sample of 1,012 Scottish adults online between November 11 and 16.