It would be "difficult, if not impossible" for an independent Scotland to join the European Union, European Commission president Jose Manuel Barroso says.
His blunt statement ramps up the pressure ahead of Scotland's key referendum on independence from the United Kingdom, following Britain's warning that it will not be allowed to keep the pound if it votes to break away.
"I believe it's going to be extremely difficult, if not impossible" because the formation of a new member from a member state needs approval from all other EU nations, Barroso told BBC television on Sunday.
Scots are due to vote on the issue on September 18 in an historic referendum that could result in the breaking up of its 300-year union.
"I don't want to interfere on your referendum here, your democratic discussion here, but of course it will be extremely difficult to get the approval of all the other member states to have a new member coming from one member state," Barroso said.
"We have seen Spain has been opposing even the recognition of Kosovo, for instance. So it is to some extent a similar case because it's a new country and so I believe it's going to be extremely difficult, if not impossible, a new member state coming out of one of our countries getting the agreement of the others."
But he added: "It's for the Scottish people ... to decide about the future of Scotland."
The comments drew a sharp rebuke from Scotland's Deputy First Minister Nicola Sturgeon, whose Scottish National Party (SNP) is spearheading the pro-independence campaign.
"This is a preposterous assertion - as the ridiculous comparison with Kosovo illustrates," Sturgeon said.
"Scotland is already in the EU and has been for 40 years.
"As Mr Barroso rightly says, the question of Scotland's independent membership of the EU is a matter for the democratic wishes of the people of Scotland and the views of other member states - not the European Commission," she said.
"The fact of the matter is that no member state has said that it would veto Scotland's continuing membership."
