BELFAST (Reuters) - A British vote to leave the European Union intensifies the case for a vote on whether Northern Ireland should leave the United Kingdom, Northern Ireland's largest Irish nationalist party Sinn Fein said on Friday.

"This outcome tonight dramatically changes the political landscape here in the north of Ireland and we will be intensifying our case for the calling of a border poll" on a united Ireland, Sinn Fein chairman Declan Kearney said in a statement.

"The British government as a direct result have forfeited any mandate to represent the interests of people here in the north of Ireland in circumstances where the north is dragged out of Europe as a result of a vote to leave," he said.