Sinn Fein's Mary Lou McDonald firm favourite to take over from Gerry Adams
Mary Lou McDonald is the clear favourite to replace Gerry Adams and become the second woman to lead Sinn Fein.
The party is expected to hold a special ard fheis in the spring to choose its next president, with many of its senior figures including Mr Adams viewing Ms McDonald as his heir apparent.
Sinn Fein's Northern Ireland leader Michelle O'Neill has ruled herself out of any leadership race.
She told the BBC she had "enough to do" in her current role and would be concentrating on dealing "with the problems in the North".
Ms O'Neill said she would see who put their name forward for the party leadership and then "make my decision on who I'd support".
Donegal TD Pearse Doherty, who last week was seen as a possible candidate, said he wouldn't be a contender.
While Ms McDonald was described by MLA Caral Ni Chuilin as "one of the most formidable women in politics", there are question marks over how well she would connect with republican grassroots, particularly in Northern Ireland.
Born in the affluent Rathgar area of Dublin and educated at the private fee-paying Notre Dame school, the 48-year-old TD for Dublin Centre was once famously filmed for a TV documentary asking "How much are the prawns?" while shopping.
A graduate of Trinity College, she joined Fianna Fail in 1997 but left a year later.
She joined Sinn Fein and unsuccessfully ran for the Dail in 2002 and 2007 before finally being elected in 2011.
She became Sinn Fein's first MEP in the Republic in 2004 but lost her seat in 2009 to Socialist Party leader Joe Higgins.
Ms McDonald has sat on the Sinn Fein ard chomhairle since 2001 and replaced Pat Doherty as the party's deputy leader in 2009.
Impeccably well briefed in comparison to Mr Adams, she is regarded as a strong Dail and media performer who also has good people skills. She has said she joined Sinn Fein to "make a difference" and has challenged the stereotype of "what a Shinner is like".
She said: "I am not uniquely a middle-class person in Sinn Fein.
"I am not uniquely university-educated. We are a much bigger social mix than people might imagine."
As the DUP's Arlene Foster was Peter Robinson's preferred heir, so Ms McDonald has the advantage of being Mr Adams' favoured successor.
She is married to gas control superintendent Martin Lanigan and they have two children.
The first woman to lead Sinn Fein was Cork republican Margaret Buckley - but her CV was very different to Ms McDonald's.
Jailed after the Easter Rising, she was later imprisoned again as a leading anti-Treatyite in Kilmainham Gaol where she went on hungerstrike, and in Mountjoy where she became 'officer commanding' of the female republican prisoners.
Ms Buckley was the first female leader of any Irish political party.
Sinn Fein's other most prominent female figure was Maire Drumm who was party vice-president for four years.
A Cumann na mBan member, she was jailed twice for seditious speeches.
She was shot dead in 1976 by loyalists in her hospital bed in the Mater, Belfast, where she was recovering from an eye operation.