The European bosses are determined to take back control of the EU and behind the scenes some officials what Britain to attend less European Union events.
A source told Politico: “Some around the dinner table in Tallinn would prefer it if May wasn’t invited to informal gatherings, and showed up only when she had to.”
The EU is battling to find its own way forward during a time of great change.
But when leaders meet in the Estonian capital today, they will not discuss the bloc.
Instead they will talk about timetables and when its best to start talking about Brexit.
The restraints come despite French leader Emmanuelle Macron laying out his vision for the future of the EU on Tuesday.
And European Commission president Jean-Claude Juncker offering up his view of how the bloc should develop, along with Mrs May’s speech in Florence, last week.
But sources told Politico that European Council President Donald Tusk does not want any more outside interference from Britain, France or any other country.
In his invitation letter to the leaders’ dinner, he detailed what they could talk about.
He clearly states that there should be no “ideas on governance” of the eurozone.
Instead, he said, the EU officials will discuss it at a meeting in December.
Mr Tusk added: “We should all be aware that Brexit remains one of the main tasks for us.
“This will be the subject of our next meeting at 27 in October, on the basis of Article 50.”
On August 24, an invitation was sent out to top aides of the EU’s 28 leaders.
The email, which was seen by Politico, announced plans for an “informal evening program for heads/delegations arriving early on 28 September.”
They will also be going to see Sting in concert.
The source added that an awkwardness has developed about the Brexit process among EU leaders and British negotiators.
And while Mrs May officially remains a member of the European Council they now see her as both a “rival and a cherished partner.”