Lawyers remain at loggerheads over Scotland’s future in the European Union if it becomes independent.
The Scottish Government insists it will keep Scotland in the EU by negotiating a treaty amendment in the 18 months after the referendum.
But many senior European figures, including European Commission president Jose Manuel Barroso and European Council president Herman Van Rompuy, have suggested Scotland would have to rejoin as a new state.
Few experts argue that Scotland would be completely ejected from the EU, and lawyers and academics are increasingly gathering around the idea that interim arrangements will be made to conserve Scots’ EU citizenship rights until full membership can be negotiated.
Three eminent lawyers told Holyrood’s European and External Relations Committee that Scotland would have to apply to join the EU as a new state, with interim arrangements to preserve Scots’ EU rights in the meantime.
The SNP’s proposed treaty amendment would be “legally implausible and incredibly politically risky”, according to Cambridge European law expert Professor Kenneth Armstrong.
But the EU will also be keen to avoid the “nightmare scenario” of depriving Scots of the EU rights and the protection of EU citizens living in Scotland, constitutional expert Aiden O’Neill QC said.
Interim arrangements are therefore likely to emerge, former Scottish Government deputy solicitor Patrick Layden QC said.
But they were all challenged by former European Court judge Sir David Edward, who said there is no provision in the treaties for interim arrangements and that Scotland’s full membership would require “relatively small” amendments to the treaties.
Sir David also took on Mr Barroso and Mr Van Rompuy, insisting that politicians were repeatedly found wrong in his 14 years on the European Court and expressing confidence that Scotland will not face the “Van Rompuy answer”.
Mr Armstrong said: “Article 49 (on accession) is the specific legal basis for dealing with an entity acquiring the status of being a member state of the EU.
“Article 48 (on treaty amendment) is to me legally implausible as it is a way of renegotiating the treaties between existing member states, and not with some other non-member state.
“More importantly, it’s incredibly politically risky.”
He added: “We know that very strong elements within the Conservative Party would want to reopen treaty negotiations on a whole host of other things, which would then bog down the entire negotiation process and may ultimately lead to its failure.”
Mr O’Neill backed the Article 49 route, but said the loss of EU citizenship rights “would create an unstable situation” that Europe would be keen to avoid.
He said: “Something will be worked out, it always is.
“If one were to posit the possible nightmare scenario of Scotland being independent outside the EU with British nationality no longer afforded to Scottish citizens, then EU nationals here are no longer within the EU and no longer have claims against an independent Scotland for their EU rights.
“But more stunningly is that Scottish nationals working elsewhere in the EU, presumably also including London, would lose all their EU rights.”
Mr Layden also backed Article 49 with interim arrangements until full membership can be negotiated.
“We could agree on a matter of international law that for whatever period we thought it would take to achieve formal membership that Scottish nationals would have certain rights in the EU and EU citizens would have certain rights in Scotland,” he said.
“It wouldn’t affect contractual arrangements and we could arrive at an interim solution.”
Sir David said the treaties “provide no machinery” for any interim solution.
“So as far as the treaties go there is no solution to this problem, but I go back to what was said to me by a very experienced Dutch foreign servant, and later the Dutch foreign minister, on the problem of the euro,” he said.
“He said: ‘We will find a way, we always do.’
“It would be the obligation of the UK to take a proposal for the amendment of the treaties to the EU to take account of the situation that will occur at the time when Scotland becomes independent.
“The number of things in the treaties that you have to amend is relatively small.”
Mr Barosso has said newly independent states “have to apply to the European membership according to the rules”, while Mr Van Rompuy said a seceding nation would become “a third country with respect to the Union”.
Sir David said: “I was judge of the European Court for 14 years. I remember repeated occasions where politicians have asserted positions which the court has found to be wrong.
“There is a gap between the vote and independence, and in that period you have an obligation to negotiate a solution to the problem. That is ignored by Barroso, Van Rompuy and all those who talk about it.
“You could mount a case before the European Court. Whether you get an answer in 18 months is an entirely different question but, please, am I going to lose my rights at the moment of independence?
“I don’t know, but I would be prepared to bet that it wouldn’t be the Van Rompuy answer.”