The Red C poll in the Sunday Business Post saw the party in third place as it dropped from 15 per cent of support in May to hit its worst popularity rating in the poll of all time.
Taoiseach Micheál Martin’s party is behind Fine Gael with 35 per cent of first preference vote intention and Sinn Féin with 27 per cent.
The party lost the most support to Independent candidates, who gained three points to capture 10 per cent of the first preference vote of those surveyed.
Support for the Government’s handling of the Covid-19 pandemic has also plummeted from an 80 per cent approval rating in a previous poll conducted in late April.
Just 36 per cent of those surveyed now say they support how the Government is dealing with the crisis, while 30 per cent disapprove and a further 30 per cent are neutral on the issue.