Sinn Fein President Gerry Adams has said Sinn Fein is strong enough in west Belfast to retain its Westminster and assembly seats without him.
Mr Adams announced on Sunday he would be stepping down as a a member of the Stormont Assembly to stand for the Dublin parliament in the next general election.
His successor in the assembly will be former IRA hunger striker Pat Sheehan.
Mr Adams will remain as West Belfast MP until the next 26-County election when he will stand in the Louth constituency.
Mr Sheehan was picked by the party at a selection convention in the Irish Republican Felons clubrooms on Tuesday evening and will be sworn in at the assembly within days.
Addressing party members, Mr Adams said: “We have no reason to fear anything - the people in this room have nothing to fear.
“It’s a challenge, we’ll meet the challenge so let’s make a stand, let’s do it together.”
Mr Sheehan spent 55 days on hunger strike in the 1981 Long Kesh prison protest that saw ten republican PoWs, including Bobby Sands, give their lives in the fight against Thatcher’s criminalisation policy.
Serving a sentence for his part in an IRA bomb attack at the time, Mr Sheehan was close to death when the protest was ended.
Imprisoned twice during the conflict before being released under the terms of the 1998 Good Friday Agreement, Mr Sheehan later filled a number of roles for Sinn Fein.
In particular, he has represented the party in the Middle East at events aimed at discussing problems in the peace process in Ireland.
The new Assembly Member for West Belfast spoke of the “sense of injustice” which led him to join the IRA as a teenager. Mr Sheehan said he was a pupil at St Paul’s Primary School at the end of Bombay Street in Belfast when it was burnt out at the start of the Troubles.
“After that we had the British Army, internment, Bloody Sunday and all of that,” he said. “I was also aware of my Irish history and all of this combined to give me a sense of injustice.”
Just 16 when he joined the youth wing of the IRA, Sheehan was first jailed at the age of 19, and, three years after being released in 1987, imprisoned again for 24 years for bombing offences.
He also recalled how loyalists came to his house in the mid-1970s and attempted to assassinate him.
While he has still officially to be sworn in, the man who took part in the 1981 hunger strike signalled his intention to hit the ground running.
“I feel very humbled by the fact the party has chosen me. I am well aware of the challenges that face us all in the future and I am up for the challenge and ready for it. I look forward to my next few months in the Assembly, and then standing for election next May,” he said.
Mr Adams said his decision to stand for the seat was sparked by concerns over the economic crisis gripping the 26 Counties, but the strategy is also seen as an attempt to boost the party in the south.
Sinn Fein currently has five MPs in the Six Counties and four TDs in the 26 Counties.