SF's Doherty tops by-election opinion poll

A new opinion poll shows Sinn Féin on course to win the Donegal South West by-election.

The RED C survey for Paddy Power shows Senator Pearse Doherty on 40% of first preference votes.

Fianna Fáil's Brian O'Domhnaill polls less than half that on 19%.

Fine Gael's Barry O'Neill is third on 15%, with 14% for Labour's Frank McBrearty Junior.