Scottish leader Nicola Sturgeon pleaded her case in Brussels on Wednesday for Scots to stay in the EU, showing how Britain's vote to leave the bloc could splinter the United Kingdom. But she drew a rebuff from Spain and a mixed response from European officials.
EU leaders met for the first time without Britain. Outgoing Prime Minister David Cameron flew home after briefing his 27 peers on Tuesday evening on last week's referendum defeat.
Sturgeon has said that Scotland, where voters backed staying in the EU by a near 2-1 majority, must not be dragged out of the EU against its will. She wants to negotiate directly with Brussels to protect the membership rights of Scots.
But Spanish Prime Minister Mariano Rajoy, struggling to prevent the autonomous region of Catalonia from breaking away, said Madrid would oppose any EU negotiation with Scotland.
If the United Kingdom leaves, Scotland leave, he said after the first meeting of the 27 EU partners without a British representative.
The 27 EU leaders sent a firm message to London that there would be no negotiations of any kind on future trade relations until the UK officially triggers the EU treaty's exit clause.
This should be done as quickly as possible, they said in a joint statement.
In a clear warning to Britain's Leave campaigners, added at the last minute, the 27 also said that access to Europe's prized single market requires acceptance of all four freedoms of movement for goods, capital, persons and services.
There has been a surge in sympathy in many parts of Europe for the 5.5 million Scots, whose strong vote to stay in the EU was overridden by the English, who outnumber them 10 to one. Britain as a whole voted 52-48% to leave.
But countries like Spain that have dealt with regional separatism are strongly opposed to any direct EU talks with Scotland. Back in London, Cameron told Parliament negotiations had to be carried out by the United Kingdom as a whole.
European Council President Donald Tusk, the chairman of the summit of EU leaders, pointedly declined Sturgeon's request for a meeting. But European Commission President Jean-Claude Juncker, head of the bloc's executive, did agree to meet her.
Some EU countries called Juncker's decision to meet Sturgeon a provocation designed to raise pressure on London to give formal notice to quit. He rejected such suggestions.
Scotland has won the right to be heard in Brussels, so I will listen carefully to what the first minister will tell me, Juncker told a news conference.
The President of the European Parliament, Martin Schulz, met Sturgeon earlier on Wednesday. She sounded a cautious note.
This is very much an initial meeting, a series of meetings in Brussels today, so that people understand that Scotland, unlike other parts, of the United Kingdom does not want to leave the European Union, Sturgeon said.
Officials briefed on the meeting said Sturgeon had discussed whether there was any legal way that a breakaway Scotland might somehow remain in the EU once the United Kingdom completed its so-called Brexit.
I don't want to underestimate the challenges that lie ahead, she said. Schulz said he had listened and learned.
EU officials stressed, as they did before Scots voted against independence in a 2014 referendum, that Scotland could not apply to join the Union until it was a sovereign state. Senior officials dismissed the notion that Scotland could take over the empty British chair at the European Council table.
Sturgeon has raised the prospect of the Scottish parliament trying to block Brexit legislation to keep the entire United Kingdom in the EU, but has also said she believes a new referendum on Scottish independence is now highly likely.
With the EU facing years of uncertainty in negotiating the withdrawal of its second-biggest economy, the Scottish factor is a complication most governments would rather avoid.
One senior EU official played down Juncker's invitation to Sturgeon, noting drily that the president likes the regions of Europe, comparing Scotland to federal states in Germany. But some diplomats saw Juncker's move as deliberate ploy to add pressure on Cameron and his successors to speed divorce talks.
This is a way of putting pressure on London to trigger the exit clause, a senior official in one EU government said of EU efforts to bounce London to the negotiating table, while Cameron has insisted only his successor will set the clock ticking on a two-year deadline to withdrawal.
The leaders launched a period of political reflection, with their next informal meeting set for September in Bratislava, culminating in a set of reform proposals to get a better grip on migration, bolstering security and creating jobs and growth.