The SDLP's Ms Annie Courtney MLA has vowed to fight a leadership attempt to have her replaced on the party ticket for the Stormont elections.
Ms Courtney said she was "not going to give up the fight" after a selection panel in Derry last night began moves to replace her next week as a candidate with city councillor Mr Gerard Diver.
Mrs Courtney was one of four candidates selected by SDLP members in Foyle last September to fight the Assembly elections.
SDLP leader Mr Mark Durkan, Assembly whip Mr John Tierney and former Derry mayor Mr Pat Ramsey were chosen to fight alongside Ms Courtney.
However, this week, Mr Tierney withdrew to take up a newmanagement role within the party.
Ms Courtney revealed on Tuesday she was coming under severe pressure from the party hierarchy to drop out.
The SDLP will reconvene a second Foyle constituency selection convention next week and seek the approval of members to replace Mr Tierney with city councillor Ms Mary Bradley and Annie Courtney with councillor Diver.
The SDLP's selection woes in Foyle have been good news for Sinn Féin which is hoping to eat significantly into the party's vote.