Support for Fine Gael is marginally ahead of Fianna Fáil, the latest Sunday Business Post/Red C poll has suggested.
Just one point separates the parties amid much speculation about when the general election will be called.
The biggest parties in Leinster House are hinting at spring or early summer next year when it comes to the timing of the next election.
But if that vote were to take place right now, it is Fine Gael that holds a slender lead on 29% - up one point on the last comparable poll in May.
The biggest increase in support was for Fianna Fáil. The party is up four points to 28%.
Sinn Féin is down one point to 12% - the party's lowest level of support in this series of polls for three years.
Non-aligned independents drop one point to 13% but the Independent Alliance, who are in Government, gain one to stand at 3%.
The Labour Party is up one point to 6% while Solidarity-PBP is down one point on 1%.
The Green Party looks to be maintaining the support levels it achieved in last May's elections; the party is unchanged on 7%.
The Social Democrats are down one point to 1%.
There is a margin of error of plus or minus three percentage points.