Sinn Fein has suffered its largest ever setback in the Irish Behaviour & Attitudes poll at the end of what has been a difficult year for the party south of the border.
The six-point slump to 17% follows the resignations in recent months of TDs Peadar Tóibín and Carol Nolan, who both oppose Sinn Fein’s liberal abortion policy.
Carried out for the Sunday Times, the final political survey of 2018 also revealed that leader Mary Lou McDonald’s personal satisfaction rating fell by four points to 44%.
This latest reversal comes just weeks after Sinn Fein’s presidential election candidate Liadh Ní Riada secured just 6.4% of the vote – less than half of that polled by the late Martin McGuinness in the 2011 contest – and is the lowest rating since Ms McDonald became leader in February this year.
Mr Tóibín estimates at least 30-40% of Sinn Fein voters in Northern Ireland have difficulty with the party’s stance on abortion, while in the south it would be a “healthy third” he said recently.
Mr Tóibín has held a number of meetings on both sides of the border to gauge support for a new, anti-abortion republican party.
Fine Gael remains the most popular party in the Republic (31%) but Fianna Fail has closed the gap to two points (29%) – recording the party’s highest rating in 18 months.