Support for Fine Gael has fallen to its lowest level in the Sunday Times/Behaviour and Attitudes series of opinion polls.
A survey of voters carried out over nine days up to last Wednesday suggests the party now trails Fianna Fáil by 11 points.
The new poll comes at the end of a difficult week for the minority administration.
The findings show that Fine Gael support is now at 21%, a drop of two points on last month.
However, for Fianna Fáil there is a three-point rise bringing its support to 32%.
It means there is now an 11-point gap between the main Government party and the party underpinning it from the opposition benches.
There were gains too for Sinn Féin, the party is up two points to 19%.
Non-aligned independents suffered a drop of seven points to stand at 8% support.
Labour is up one point to 6%, the Independent Alliance is at 5%, and the AAA/PBP is on 3% support.
The Greens and the Social Democrats are each on 2% and the Workers' Party is at 1%.
The margin of error is 3.2%.
