An independent Scotland would have to apply for membership of the European Union, the SNP has conceded.
Deputy first minister Nicola Sturgeon conceded in a Brussels speech that membership would have to be negotiated, after the Scottish government had suggested a newly independent Scotland would join the EU automatically.
"We would begin as a nation keen to be an equal and constructive partner in the EU - recognising its benefits, participating in dialogue about its future and contributing to its development and growth," she told the European Policy Centre thinktank.
In London, the Scotland Office described her shift as a "major concession".
It had insisted Scotland would not be able to retain all the benefits of EU membership if it voted to become an independent nation - a critical issue in next year's referendum campaign.
Sturgeon acknowledged the Scottish are less eurosceptic than those in the rest of Britain.
"This divergence of views between Scotland and elsewhere in the UK is not a recent or short-term phenomenon," she added.
"While I would not suggest that it doesn't exist at all, it is nevertheless the case that euroscepticism has never had the same potency in Scotland as it does in parts of England."
If Scotland votes 'yes' in autumn 2014 it will also face a tough renegotiation of its relationship with the rest of Britain, which the UK government played up in a legal note issued earlier this month.
"The legal opinion published today, which the UK government agrees with, would mean a newly independent Scottish state being required to create a new set of domestic and international arrangements," international law experts Professors James Crawford and Alan Boyle concluded.
"Negotiations would need to take place with the UK government on any requests to retain UK wide arrangements on matters such as a currency union, financial regulation and national security. An independent Scotland would also need to negotiate with the European Union to agree new terms and conditions."
Britain, by contrast, would not be obliged to renegotiate any of its existing international treaties or memberships.
"The position of the European Union is unique in many ways- it has its own body of law, its own institutions, and in that sense is unlike any other international organisation – it is a 'new legal order of international law'," advocate general Lord Wallace said.
"Nevertheless, Professors Boyle and Crawford point out, it is an international organisation, and in the absence of any specific provision in its rules to the contrary, a new state such as Scotland would not join automatically on separation from an existing member state.
"There is no explicit treaty provision for this process in the EU’s own membership rules, and so there is no reason to think that Scotland would be entitled to join without some form of accession process, and therefore no basis on which Scotland could somehow automatically inherit the UK's existing opt-outs."