The Scottish Government is "considering" whether to put pressure on UK ministers to obtain a specific legal opinion on Scotland's place in the European Union.
Only the British Government can request the view of the European Commission but no such request is likely to be made.
If that policy remains, voters could be left without key information on Scottish independence in the EU until after the referendum in autumn 2014.
Asked if the Scottish Government will now press Westminster counterparts for answers, a spokesman for the First Minister said: "It is a matter for the UK Government."
He later added: "We will consider our options in this matter as we move forward. At this stage, the European Commission have offered to provide legal opinion on an independent Scotland's continuing membership of the EU to the UK Government, as the relevant member state, an offer the UK Government has so far declined to take up."
The issue of European statehood dominated First Minister's Questions for the second week in a row at Holyrood, where Alex Salmond faced criticism from Labour, Tories and Liberal Democrats.
Mr Salmond insists Scotland will be "welcomed with open arms" after a Yes vote but others point out there is no legal precedent and no guarantee of a smooth transition.
Labour leader Johann Lamont led criticism of Mr Salmond at Holyrood, telling MSPs: "The charge at his door is that he asserts things for which he has no evidence and it is about time that the First Minister got serious about the future of Scotland."
Tory leader Ruth Davidson said: "We know now that the the First Minister has no legal basis for his claims about Scotland's place in Europe."
Lib Dem leader Willie Rennie said it is unlikely Scotland would not be in the EU, but said questions remain about the terms of membership.