Support for the government parties has risen in the first opinion poll since the summer break.
A Red C poll for tomorrow's Sunday Business Post shows rising support for both Fine Gael and Labour.
The poll, taken between Monday and Wednesday of last week, came in the midst of outcry about the status of the IRA and its potential impact on Sinn Féin's power in the North.
The poll of just over a thousand adults shows Sinn Féin support down two points to 16% - its lowest poll rating in more than 18 months.
However, with Fianna Fáil unchanged on 18%, it is the government parties who make the gains ahead of the Budget and a possible early election.
Fine Gael are up three points compared to the last poll at the end of July, and are now at 28%, while Labour are up two points to 10%.
Their gains means independents and smaller parties also suffer as their share of the vote falls three points to 28%.