Sinn Féin and the Green Party have fallen
The election of Leo Varadkar as Taoiseach has given Fine Gael a boost among voters.
A newIrish Daily Mail-Ireland Thinks opinion poll puts the party on 31% - a six point increase compared to a similar poll in April.
Fianna Fáil is down one point to 26%, Sinn Féin and the Green Party also fall one to 16% and 4% respectively.
The Labour Party sees good news - it is up two points to 7%.
The Social Democrats are down two to 2%, while Solitary-People Before Profit are down one to 2%.
Independents have dropped four places to 11%.
The poll was carried out over five days on the week Mr Varadkar succeeded Enda Kenny as Taoiseach.