Margaret Ritchie has announced that she is to step down as leader of the SDLP.
The South Down MP was facing a challenge to her leadership from the party's deputy leader, Patsy McGlone.
He announced that he would contest the leadership at the party's annual conference in November following poor Assembly election results in May.
Margaret Ritchie was elected leader of the SDLP in January 2010 but had been under pressure since the Assembly elections.
The Tánaiste and Minister for Foreign Affairs has said that Ms Ritchie was a phenomenal vote-getter in South Down and an excellent Minister for Social Development in the Northern Ireland Executive.
Eamon Gilmore said she had a unique insight into how politics north and south worked.