Support for Sinn Féin has increased to 34%, the latest Sunday Independent/Ireland Thinks opinion poll suggests.
It represents a 3% increase on the previous comparable poll, which was carried out at the start of July.
The poll also suggests an increase in support for the Green Party - up from 3% to 5% - and for Labour, which has risen from 2% to 4%.
Fine Gael has held steady when compared with last month's poll at 19%.
Coalition partners Fianna Fáil have fallen slightly to 18%, down from 19% last month.
The Social Democrats have also fallen by one percentage point from 6% to 5%.
Solidarity/People Before Profit and Aontú polled at 3% and 2% respectively, both down one percentage point from the July poll.
Finally support for Independents and others has fallen by three points to 10%
The Sunday Independent/Ireland Thinks poll was conducted today and yesterday.
It surveyed 1,272 people and has a margin of error of +/- 2.8%.
