1986 Belfast East by-election1986 Belfast North by-election1986 Belfast South by-election1986 East Antrim by-election1986 East Londonderry by-election1986 Fermanagh and South Tyrone by-election1986 Lagan Valley by-election1986 Mid Ulster by-election1986 North Antrim by-election1986 North Down by-election1986 South Antrim by-election1986 Strangford by-election1986 Upper Bann by-election