The UK will retain full EU membership rights for two years while the terms of its departure are negotiated. Britain is scheduled to claim the EU's six-month presidency from July to December 2017
But it is seen as highly doubtful that it could be at the helm of the EU for six months while it is in the middle of negotiations to leave.
Malta assumes the presidency in January and Martin Selmayr, chief of staff to Commission President Jean-Claude Juncker, is said to have told Maltese officials to prepare for an extended EU Council presidency.
EU treaties state that officials representing a member country heading to the exit "shall not participate in the discussions of the European Council or Council or in decisions concerning it."
Former Liberal MEP Andrew Duff, a constitutional expert, said, "Certainly the British would ask to be relieved of the responsibility to be President."