The UK government's Scotland secretary has raised the prospect of border checks between England and an independent Scotland ahead of a major anti-independence speech from prime minister Theresa May.
Speaking ahead of the Scottish Conservative conference this weekend, where May will make her case for Scotland's place in the UK, David Mundell told BuzzFeed News the Scottish government's proposals for independence inside the EU would almost certainly lead to "border arrangements" with England.
However, Mundell added that he doesn't believe another independence referendum in Scotland is inevitable despite Nicola Sturgeon repeated statements that she believes it's "very likely".
"It’s difficult to see, given some of the policies the SNP say they want to pursue, how it would be possible not to have border arrangements," said Mundell.
"If they had a significantly different immigration policy to the rest of the UK, it’s difficult to see how that could be enforced without border arrangements – and the sort of policies they say they’re going to pursue are the sort of policies that would lead to border arrangements."
Mundell's comments came after a speech from Jeremy Corbyn at the Scottish Labour conference last Sunday in which he said an independent Scotland inside the EU would lead to a "hard border" with the rest of the UK and would force the country to adopt the euro.
Sturgeon, the first minister, has previously dismissed the prospect of a hard border between an independent Scotland and the rest of the UK, saying the prime minister had assured the Irish government that she doesn't want to see a hard Irish border.
Sturgeon said in December: "Talk of a hard border for Scotland has always rung hollow from a UK government that says no such hard border will be required between a post-Brexit UK and the Republic of Ireland."
However, Mundell said Sturgeon's dismissal of the prospect of a hard border between Scotland and the rest of the UK proved that she believed in independence "regardless of the consequences".
Mundell said: "I find incredible that we hear a really strong focus from the SNP on the single market in the EU but they seem quite happy to disregard the UK domestic single market with no tariffs and barriers, and don’t seem concerned whether those would exist in the future."
The Scottish secretary refused to be drawn on whether the UK government is making contingency plans for another referendum on independence, instead insisting it will continue to make the case at the conference that there shouldn't be another vote for a generation.
"We’re making the argument that there should not be another referendum because people have made their choice previously," said Mundell. "But, within that, I’m sure the prime minister in Glasgow will clearly make the case for the UK.
"It’s not just about saying no to another referendum, but it’s also continuing to make the case for the UK and we’re in very good shape to do that."
The Scottish Conservative conference begins on Friday.