The latest Red C opinion poll shows that Fine Gael is the most popular political party, but that Fianna Fáil are drawing close at just two points behind.
The survey in the Sunday Business Post puts Enda Kenny's party unchanged at 28%, while support for Fianna Fáil has risen by five points to 26%.
It is the third opinion poll in a month recording the re-emergence of Micheál Martin's party.
Labour have notched up one point bringing them to 12% while Sinn Féin and the Independents have each dropped by three points.
Political Editor of the Sunday Business Post Pat Leahy said the growing Fianna Fáil recovery could not be denied.
"We've seen this trend emerge over the last six months. Today's numbers show an acceleration of that trend," he said.
"What today's poll shows in that it is stronger than we had previously understood, but the fact of the Fianna Fáil recovery is now unchallengeable."