Northern Ireland elections on Thursday could mark a major shift in the region’s sensitive political balance, and undermine Boris Johnson’s bid to redraw the terms of the U.K.’s split from the European Union.
Opinion polls show Sinn Fein — whose ultimate goal is to unite the region with the Republic of Ireland — on course to become the biggest party. That would be the first time for a nationalist party since Northern Ireland’s power-sharing assembly was born out of the 1998 Good Friday agreement, which largely ended decades of violence between unionists and nationalists.