The European Commission has asked Nobel Peace Prize laureate Martti Ahtisaari to try to resolve a long-standing border dispute between Croatia and Slovenia, officials in Brussels said. Ahtisaari, a diplomat who formally worked as a United Nations special envoy to Kosovo, was approached by the EU’s enlargement commissioner, Olli Rehn, in a bid to end a stalemate that risks jeopardising Croatia’s rapid entry into the bloc.

“Commissioner Rehn has discussed with president Ahtisaari and explored whether he would be available to chair a senior expert group in order to facilitate a solution on the border issue between Slovenia and Croatia,” said Rehn’s spokeswoman, Krisztina Nagy, whostressed that any decision on the setting up of such a group would first have to be agreed by both sides.

The row between the two neighbours erupted when Slovenia challenged the borders drawn in the former Yugoslavia following its disintegration in order to gain better access to the northern Adriatic Sea. The existing border seals Slovenia - including its fishing fleet - within the tight bay of Piran, with Croatia claiming one end and Italy the other end of the bay.