Pat Rabbitte today ruled out leading the Labour Party into a coalition with Fianna Fáil.
Mr Rabbitte ended a long period of uncertainty over his position by stating in a radio interview this morning that he had staked his reputation on the Mullingar Accord - the pre-election pact with Fine Gael.
Mr Rabbitte told listeners on RTE radio's Today with Pat Kenny: "I have no intention of doing any business with Fianna Fáil."
Labour leader Pat Rabbitte
He was answering a question from a party member expressing concern that Mr Rabbitte's refusal to rule out entering coalition with Fianna Fáil could lessen the transfers the party attracts from Fine Gael.
In the 2002 general election, the Labour Party led by Ruairí Quinn expressed a preference to enter government with Fine Gael but refused to enter a pre-election pact.
Mr Rabbitte opposed the strategy - which was widely regarded as costing the party votes - and favoured a formal pact with Fine Gael.
When he became leader, he immediately committed himself to removing Fianna Fáil from power and in 2004 agreed to formally offer the electorate a Labour/Fine Gael alternative at the next election.
But despite being repeatedly questioned about his position on working with Fianna Fáil, Mr Rabbitte had, until today, refused categorically to rule out the party out as a potential coalition partner.
However today he said: "As regards the electoral strategy I have risked my reputation as leader in constructing a platform with Fine Gael in order to ensure that the people will have the opportunity of an alternative government, and I have no intention of doing any business with Fianna Fáil."
When pressed by Pat Kenny whether there was "no possibility" of a coalition with Fianna Fáil, Mr Rabbitte said: "As far as I am concerned, Pat, there isn't."
This evening on TV3's Polls Apart with Cooper and HobbsMr Rabbitte was asked if Brian Cowen became leader of Fianna Fáil would Labour then think about forming a government with them.
However, Mr Rabbitte said he didn't make his decisions based on personalities.
"I think its wrong at this juncture in the country's history for me to be responsible for putting Fianna Fáil back in power when the majority of the country want them out," he added.