Samuli Virtanen told reporters Brussels was having trouble dealing with the UK due to splits within her Cabinet and a lack of direction over the kind of future partnership it wants with the EU.
His alarming comments reflect a deep-seated nervousness within European capitals that Britain is all at sea over Brexit, but are amongst the most blunt to be publicly delivered by a senior figure.
EU officials have been privately concerned for some time over a lack of clarity from the UK over the kind of cooperation it wants with the bloc on both trade and other matters beyond 2019.
This is despite the fact that it is the British side that has been pushing hard for the other member states to declare “sufficient progress” has been made in the first round and open trade talks.
Mr Virtanen, the State Secretary at the Finnish Ministry of Foreign Affairs, made the remarks arriving at a meeting of the General Affairs Council in Luxembourg, at which the EU27 were set to discuss their draft conclusions on the divorce talks so far.
He was asked whether or not he had sympathy for Mrs May’s “difficult” political position at home, where she is trying to balance Remainer and Leaver elements within her Cabinet.
He replied: “It is and that’s one of the things that makes the situation on the negotiating process a bit difficult because it seems that at the moment the EU27 is more unanimous than the UK one.
“So that’s one of the main problems here. When we read the British press for the situation in Westminster sometimes it’s very difficult to see and understand what Britain really wants from these negotiations.”
The remarks are likely to be pounced upon by opposition politicians in the UK to accuse the Government of muddled thinking over Brexit and failing to clearly communicate its position to Brussels.
In her Lancaster House speech Mrs May said Britain will be leaving the Single Market and Customs Union but did not elaborate on how it intended to maintain good market access after Brexit.
Then, in Florence last month she ruled out following the Canada and Norway models, indicating she wanted something in between the two, but again did not clearly spell out what that would be.
Mrs May has however said Britain will not continue to accept free movement of people – one of the four fundamental freedoms of the Single Market – after Brexit which limits the UK’s options for full or close to full access.
Mr Virtanen also said that he felt the financial settlement is now the single biggest issue blocking progress in the Brexit talks, and that it needs to be unblocked to achieve sufficient progress.
He batted away suggestions that the bloc is beginning to fall out over the issue of starting transition talks, after the Belgian deputy PM expressed frustration at some members apparently stalling the talks.
He said: “The EU27 is unanimous here we’re on the same lines. I think we should find some kind of solution about the money it’s one of the most difficult issues, we should see some progress on monetary issues.”
The EU Council is set to declare that there has been no sufficient progress in the Brexit talks when it meets later this week. However, the UK has been offered an olive branch with the news that member states will begin internal preparations for a post-Brexit trade deal.