Support for Sinn Féin has risen to its highest level in two years, according to the latest Red C Poll for the Sunday Business Post.
Mary Lou McDonald's party has gained five percentage points and now stands at 18%.
The poll was taken following the party's decision to table a no-confidence motion in the Minister for Health Simon Harris last week.
Fianna Fáil has also made gains. The party is up two points to 24% while Fine Gael has dropped one point to 31%.
Independents are up one point to 15% while the Labour Party is down one point to 5%.
The Independent Alliance is down three points to 2%, while the Social Democrats are unchanged on 2%.
The Green Party is down one point to 2%, Solidarity People Before Profit are down one to 1%.
Both Renua and Aontú are showing support levels of less than 1%.
The telephone poll of 1,000 people was carried out by Red C between 14-20 February and has a margin of error of plus or minus 3%.