The plan for an independent Scotland fronted by Nicola Sturgeon could be impacted after the report revealed Scotland would have to take on the EU currency if it hoped to re-join the union.
Four separate EU sources told The Times that any Scottish application for membership would be dismissed without a pledge to sign up to the Euro.
Last week, the first minister launched her economic argument in a series of papers outlining the benefits of an independent Scotland.
Ms Sturgeon committed to rejoining the EU, proposing Scotland would adopt a new currency ‘as soon as practicable’ after using the pound sterling for ‘a period’.
However, it is not yet clear when and how this new currency system would be introduced if Scotland becomes independent.
The economic paper outlined that Scotland should re-join the European Union (EU) to “benefit from, and contribute to” the European Single Market.
During her press conference on the economic paper, the FM insisted using the Euro was not “the right option for Scotland” and her deputy John Swinney later said he believed Scotland would become an EU country using its own currency within a decade.
Yet, a source told The Times: “all EU member states, except Denmark, are required to adopt the euro and join the euro area,” while another senior source said: “No euro, no membership.”
Seven of the 13 countries that have joined the EU since 2004 have switched to the euro, most recently Lithuania on January 1, 2015.
Croatia will continue to use its own currency, the kuna, until January next year and then will adopt the Euro from then onwards.
It is understood EU member states have become more opposed to new applicants who reject the single currency since the 2016 Brexit vote.
A paper on EU membership will be published as part of the Scottish government’s series of policy documents on independence.
The economic paper also looked at establishing an independent Scottish Central Bank with oversight of monetary and economic conditions in Scotland.
Nicola Sturgeon said Scotland would have a “moral” duty to take on a share of UK debt if it becomes independent.