British Prime Minister Theresa May will tell European leaders there will be no second referendum on Brexit when she addresses them for the first time in Brussels.

Mrs May will tell counterparts that the "priority now has got to be looking to the future" as she sets out Britain's position at a European summit.

No 10 said there had been suggestions in Europe that Britain would revisit the June 23 referendum decision so the PM will use the meetings to make it clear that it is "right and proper" that the result is "honoured".

One source said: “"There has been a sense that there is still some debate in certain quarters of the European Union about whether that might be still a possibility and the Prime Minister has been absolutely clear many times that is not the case, but it is an opportunity for her to say that directly to all leaders precisely because we do need now to all be focusing on the future, which is the UK outside the European Union.”

The PM will also "reassure" other leaders that Britain will be a responsible EU member while it remains in the bloc.

Migration is the first formal item for the European Council meeting and Russia's bombing campaign in Syria will dominate discussions in the evening.

Mrs May will attempt to ease the concerns of other leaders who fear they will be harmed by Britain's exit from the bloc by vowing to deliver Britain's departure in the "best possible way", which means not just a good outcome for the UK but "how we can make it work for the EU too".

The PM will hold talks with Estonian Prime Minister Taavi Roivas and Romanian president Klaus Werner Iohannis in the margins of the summit.