The Labour TD for Limerick East, Ms Jan O'Sullivan, has declared her support for Mr Pat Rabbitte in the contest for the party's leadership.
Ms O'Sullivan had been mooted as a candidate herself in the wake of Mr Ruairí Quinn's decision to step down, but decided not to contest even the deputy leadership, for which she has nominated Ms Joan Burton.
She joins TDs Mr Emmet Stagg, Ms Kathleen Lynch and Mr Jack Wall in supporting Mr Rabbitte.
Ms O'Sullivan said she had chosen the former Workers Party and Democratic Left TD as the person best able to oppose both the Government's fiscal "incompetence" and what she said was its tolerance of corruption.
Speaking on the local radio station Clare FM, she added: "I am supporting Pat Rabbitte because I believe he is the strongest and most effective political leader available to any party in the country at the moment and, if the Irish people need anything, they need strong, committed and honest leadership.
"There is deep disillusionment at the way the current Government parties have tolerated and protected corrupt practices, and wasted the good years without using the money to make a better life for the less privileged.
"In three years those elected to lead us at the last election and the previous election have brought us from the champagne to the hair-shirt, and neglected to use the boom to meet the needs of those who cannot afford such basics as a home, or adequate healthcare.
"There should have been no champagne until services had been provided for children, senior citizens, the ill and the disabled."
Mr Rabbitte had a record of sustained work "rooting out corruption in the DIRT inquiry," Ms O'Sullivan said:
"He has the substance to make changes happen, and the ability to clearly and concisely articulate what the Labour Party wants to achieve. The country has huge potential but is rudderless because of weak leadership," she said.
