Former deputy Labour Party leader Brendan Howlin has ruled out entering the race to succeed Pat Rabbitte.
Speaking on RTÉ radio this morning, the Wexford TD and current Leas Ceann Comhairle said he had decided against entering the race following a weekend of considering his options.
Mr Howlin twice ran unsuccessfully for the leadership in the past.
Former deputy Labour Party leader Brendan Howlin
"I haven't the passion for it that is sufficient for me to go 100 per cent - firstly on the hustings to win the leadership, then for five years in unrelenting effort to build this party into greatness" he said.
"Now I want to play my role in that and I will. I will very enthusiastically support whoever is elected", Mr Howlin added.
Eamon Gilmore is expected to become the first candidate to formally enter the leadership race for the Labour Party when he announces his candidacy early this week.
Other TDs who are likely candidates include finance spokeswoman Joan Burton, deputy party leader Liz McManus and Dublin-based TD Tommy Broughan.
Meanwhile Limerick East TD Jan O'Sullivan tonight announced she was putting her name forward for the post of deputy leadership.
Ms O'Sullivan, who is the party's spokeswoman on education and science, said she was "very keen to participate at the heart of the next phase of the development of the Party".
Mr Rabbitte resigned the party leadership last week.
The party's national executive council will set a date next Saturday for a deadline for submission of nominations for leader and deputy leader, with a replacement for Mr Rabbitte due by mid-October.
Members who have paid two years' consecutive membership fees have a vote. There are approximately 8,000 members and an estimated 4,000 members are thought to be eligible to vote.
Mr Rabbitte said yesterday that he would support whoever was elected as leader. In an interview with RTÉ, he said a challenge for the new leader would be to boost its organisation on the ground and communicate the party's ideas in a strong and relevant manner.