The Dublin study found that people in areas traditionally known as Celtic, such as Ireland, Wales, Scotland, Brittany and Cornwall, had strong links with each other and had more in common with people from the Iberian peninsula.

There are also close links between Scotland and Ireland dating back much further than the plantations of the 1600s when many Scots moved to Northern Ireland in search of fertile farming lands, the research showed.

Stephen Oppenheimer, professor of clinical socio-medical sciences at Oxford, said that the Celts of western Scotland, Wales, Ireland and Cornwall were descended from an ancient people living on the Atlantic coast when Britain was still attached to mainland Europe, while the English were more closely related to the Germanic peoples of the interior.