Dublin West TD and party finance spokeswoman Joan Burton has announced her candidacy for the deputy leadership of the Labour Party.
Ms Burton's statement ended speculation that she would put herself forward to succeed Pat Rabbitte, who resigned as party leader last week.
In a statement, Ms Burton said: "In the course of my discussions with party members in the past week I recognise that I do not have sufficient support to continue with any bid for the leadership."
Ms Burton said, however, there was "a genuine representative groundswell" of support to secure her election as deputy leader. She now proposes to seek that post with the support of "a wide group of TDs, senators, councillors and constituency officers.
Dublin West TD, Joan Burton
"I intend to mount a friendly but robust campaign for the position and we will invite the members to make a considered choice between the candidates based on their manifestos and on their records," Ms Burton said.
Waterford TD Brian O'Shea today came out in support of Ms Burton, saying she had a unique capacity to maximise the potential of the role and to modernise and energise the party.
Ms Burton also received the backing of Cork senator Michael McCarthy who described her as a person of "utmost integrity". "Her ability as a parliamentarian and public representative is indisputable," he said.
Dún Laoghaire TD Eamon Gilmore formally announced his candidacy for the leadership on Tuesday. He is the only candidate to officially declare for the leadership post and is currently the favourite to win a ballot of party members in October.
Other possible contenders for the leadership position who have yet to declare their intentions include Dublin North East TD Tommy Broughan, and the acting leader, Wicklow TD Liz McManus.
Limerick East TD Jan O'Sullivan has put herself forward for the deputy leadership position and Cork South Central TD Ciarán Lynch said this week he would consider running.
Róisín Shorthall of the Dublin North West constituency confirmed last night she would not contest the deputy leadership position.