Brexit: EU pledges to May unlikely to placate critics
Led by German Chancellor Angela Merkel, the other 27 leaders spent almost an hour last night asking Theresa May questions.
What reassurances did she seek on the Irish backstop? How did she intend to get the Brexit deal through parliament? What was her vision for the future relationship between the UK and the EU?
A diplomatic summary of the meeting seen by the BBC said her answers were "not really clear".
"Bad" and "pretty bad" is how it was described by some usually-optimistic diplomats.
The lack of precision made the EU wary of offering anything too detailed in the written summit conclusions.
Ireland added wording about the backstop being a Europe-wide issue, not just an Irish one.
The backstop is described as an insurance policy to keep the Northern Ireland border open, as it is now.
There was no support for Paragraph Five of the draft document, which committed the EU to explore other options to assist the UK.
That came as a surprise to the British government, which had secretly helped to draft the summit statement.
But European diplomats said that David Cameron's renegotiation of the UK's membership, before the UK's 2016 Brexit vote, played on the leaders' minds - why offer anything that would instantly be ripped apart, or wouldn't work?