Pressure is growing on Gerry Adams after his vice president Mary-Lou McDonald confirmed she could run for his job.
Ms McDonald said she doesn't believe current party president Adams will step down in the next two years.
But for the first time she has indicated that she will be throwing her hat in the ring, even hinting that this may happen in 2016, the centenary of the Easter Rising.
Her confirmation that she would consider running for the post comes at a time of increasing pressure on Mr Adams after his brother's conviction for sex abuse and questions over Adams handling of cases of the IRA's Disappeared. He has always denied any involvement in the IRA's activities.
There has been mounting speculation about whether Mr Adams will stay on as leader following allegations that he withheld information about his brother Liam's abuse of his own daughter Aine. A documentary about the Disappeared and then Mr Adams own reaction to the Smithwick Tribunal report – claiming that murdered RUC Superintendent Bob Buchanan had not taken his own security seriously – were damaging.
However Ms McDonald says she has confidence in the Louth TD.
"I think by any standards Gerry has been an exceptional leader, he is great to work with," she told the Irish Sunday Mirror. "He has been my political mentor for more than a decade. We are good friends apart from anything else.
"But he is a good man to work with, there is no ego, he lets people find their feet and make their mistakes. He has my full confidence."
Despite this, Ms McDonald also went on to say: "nobody stays in their jobs forever. People move on", before declaring her ambition to become the next leader.
"A time will come when Gerry will step aside and the leadership will change," she said.
"I don't see that happening this year or next year.
"As and when that situation arises, I would consider my own position in terms of going forward for that."