It has long been Northern Ireland that has bedevilled efforts to negotiate an orderly Brexit, but now another British territory has emerged to haunt the talks: Gibraltar.
A Spanish migrant rescue boat that has been rejected by Italy and Malta has docked in Spain amid a heated debate over which countries will accept the 87 refugees on board.
Berlin has concluded a deal with Madrid for Spain to take back migrants registered by Spanish authorities, as Germany seeks to curb new arrivals.
Spain is not the only EU country that does not recognize Kosovo's independence - Greece, Cyprus, Slovakia and Romania also non-recognizers, however, their leaders will still attend the summit.
With naval power Britain at the EU's exit door, Spain has gone on the offensive to be the next major player defending European shores.