The Fianna Fail leader Micheal Martin is insisting his government will not go into coalition with Fine Gael after the next general election.
Mr Martin says he is hearing a lot of resistance from voters to what the bigger government party is doing in office, and claims there has been a drift to the right in the economic policies of Fine Gael.
He is also adamant that Sinn Fein is not a prospective partner in coalition.
Mr Martin has also denied that his job is on the line if the party cannot win one of the Dáil by-elections. He says he has no plans to reconsider his position if they do not go Fianna Fail's way.
Despite being the biggest opposition party, it has not won any of the four by-elections since leaving government in 2011.
The most recent Red C opinion poll from The Sunday Business Post sees the party at 18%.
Mr Martin told Newstalk Breakfast that he does not see his leadership under threat.
And he says his party will not form a government with either Fine Gael or Sinn Fein.