Fine Gael and Fianna Fáil have seen their support rise, according to the latest opinion poll.
Reacting to today's opinion poll in the Sunday Business Post, Sinn Féin leader Mary Lou McDonald says it will not change her party's message.
She said: "As the leader of Sinn Féin our job is to represent communities, represent people, to represent them well, to be true to the mandate we have.
"And in advance of the next election, which will be the poll that actually matters, to go with a sense of purpose, with a sense of energy and humility and to put ourselves before the people and to win as much support as we can."
The Red C poll for the Sunday Business Post continues the trend of many seen over the last year.
Fine Gael are the most popular party in the country on 34% - up one point in a month of tax-cut promises from Leo Varadkar.
Fianna Fáil trail on 27%, up two compared with last month's figures.
Sinn Féin are down two points to 13% in the wake of a poor Presidential election campaign.
Labour are up one to 6%, with the Independent Alliance also up one to 5%.
Independents overall, however, have seen their support drop by two points to 10%.
The Green Party are down one point to 3%, with the Social Democrats unchanged on 2%.