British diplomats were amazed that Mr Juncker appeared to be heading in the opposite direction to most elected leaders who have been alarmed by public unease over security and immigration in the borderless zone.
One British official said: “Theresa May would certainly not agree with him.”
The summit with Mrs Merkel, Mr Renzi and Mr Hollande was being staged to agree how to respond to the UK’s Brexit vote. The trio are likely to press Britain to spell out the sort of relationship it wants with the EU and to start the formal exit process by June at the latest.