The Red C poll in tomorrow's Sunday Business Post also shows support for the Progressive Democrats down to just 1%.
Fine Gael is also down by one point to 30 % while Labour increases support by 1 %, to 11%.
The Greens are also up one point, to 8% while Sinn Féin at 9% is also up one point.
Independents and others, meanwhile, have seen their support increase by one point, to 7%.
The poll was conducted on either side of the Easter weekend - after the latest revelations from the Mahon Tribunal about the Taoiseach's personal finances, but before the Progressive Democrats and The Green Party called on Mr Ahern to clarify the issues involved.
