Support has increased for Sinn Féin and the unaligned Independents, according to a poll carried out for the Sunday Times.
The Behaviour and Attitudes poll suggests Fianna Fáil has the most support among voters but both that party and Fine Gael are each down two points since July.
Sinn Féin are up four points to 18%, while Independents are also up four points to 12%.
Fianna Fáil support has dropped by two points but that party is still the most popular with voters on 28%, the poll suggests.
Fine Gael has dropped two points to stand at 23%.
The Labour Party is up one point to 7%.
The Independence Alliance are static on 4% despite John Halligan's run-ins with the Government over services at University Hospital Waterford.
The AAA/PBP are also on 4%, the Greens are on 2%, while the Social Democrats and the Workers' Party are each on 1%.
The poll was taken over 11 days up to last Wednesday. The margin of error is 3.3%.