Leaving would create the need for a hard border between an independent Scotland and England, a new report has claimed.
The report, called How the United Kingdom Might Leave The European Union, was produced by the UK in a Changing Europe group for the Political Studies Association.
The Scottish Government’s blueprint for a special post-Brexit deal between Scotland and the EU is due to be published by the end of the year.
It will explain how ministers believe the country could maintain membership of the single market even if the rest of the UK leaves.
But experts have suggested the case for independence is likely to suffer unless all of the UK remains in the single market.
They said the idea of “independence in Europe is based on the logic that with both Scotland and the UK in the EU, trade and border issues between the two would be unproblematic”.
They added: “But with Scotland in and the UK out of the EU, there would be a hard border between the two.”
They also said that polls do not suggest Scottish voters would be ready to give up the UK market in return for access to the European one.
The report warns Brexit will have a “big impact” on devolution. What form that will take remains to be seen.
Professor Anand Menon, director of the UK in a Changing Europe project, said: “Brexit has the potential to test the UK to its limits.”