A senior British official made clear during a meeting with ambassadors from European Union countries in London this week that his government wants a signal from the EU about what kind of Brexit deal it is willing to accept before triggering divorce talks, EU sources said.
The meeting, the first of its kind, was held on Tuesday so that Oliver Robbins, the top civil servant in the British Department for Exiting the European Union, could brief UK-based diplomats from EU states on the status of Brexit preparations.
It was held at the invitation of the Slovak presidency of the EU, according to one source. The Slovaks declined to confirm or comment on the meeting. The UK government did not respond to a request for comment before publication.
That it took place at all is a sign the process of sounding each other out on the nature of a deal has begun, despite the EU's insistence that no negotiations can take place before Theresa May's government invokes Article 50 of the EU treaty.
Sources who were briefed on the exchange said Robbins gave no signals at the meeting about when May might do so.
One source said he had made clear that controlling migration would be the government's top priority and that retaining access to the single market in financial services was another goal.
But several other sources said it was not clear that the British government had settled on any clear priorities and was mainly interested in ascertaining what options might be possible in negotiations before triggering the process.
The message was: we want to be able to look into your faces and get a sense of whether what we propose is reasonable. We want to avoid surprises," one of the sources told Reuters.
Another said: "They do not seem to have made up their minds about anything."
European Council President Donald Tusk and Irish Prime Minister Enda Kenny have both said in recent days that May's government is indicating it could be ready to launch formal negotiations to leave the EU in January or February of 2017.
Because this would start the clock ticking on an extremely tight two-year deadline for completing the divorce, British officials have been pushing behind the scenes for early consultations with the EU.
"The British have realised that the timeline is very short and issues very complex," the first source said.
EU member states have sent out different signals on what kind of agreement might be acceptable. But there is a broad consensus that if Britain places limits on free movement it will be difficult for it to retain access to the EU's single market.
Above all, EU member states want to avoid granting Britain a generous deal that might encourage exit referendums in other EU countries, with some saying a final agreement must painful.
Former French Foreign Minister Michel Barnier, appointed by European Commission President Jean-Claude Juncker to lead the Brexit negotiations with Britain, is expected to travel to EU capitals after he starts the new role on Oct. 1 to gauge the mood, sources told Reuters earlier this week.