Xavier Bettel
The European Commission president said his meeting with Boris Johnson on Monday was "rather positive".
Social media has a field day after Xavier Bettel gives PM the 'empty chair'.
Even tiny countries like Luxembourg can have a big role in deciding the future of the UK.
Luxembourg's refusal to move event inside and away from booing pro-EU protesters described as "extraordinary" by UK government, as Brussels demands concrete Brexit proposals from the prime minister.
PM cancels appearance after crowd holding anti-Brexit signs and singing 'Ode to Joy' turned out to greet him.