An ex-IRA man who served 15 years in Long Kesh is set to stand against Sinn Féin in West Belfast in the North's council elections.
Republican sources said Padraic McCotter, who is related to former IRA chief-of-staff Seamus Twomey, is planning to contest the seat for Éirígí in the 5 May poll.
McCotter was on the dirty protest in Long Kesh where at one stage he was second-in-command of IRA prisoners. His brothers, Sean and Liam, have also been jailed for IRA activities.
He had remained loyal to the Sinn Féin and IRA leadership for many years, including after the ceasefire and Good Friday Agreement. However, sources said he had become very disillusioned in recent times.
Ex-Sinn Féin Assembly member Davy Hyland is to stand as an independent in the council elections in Newry. He is backed by an alliance of groups including Éirígí, the 32 County Sovereignty Movement, and Republican Network for Unity.
Hyland said: "Many people in the republican community see the way things are working and believe core republican principles have been abandoned." Bernice Swift, a Fermanagh councillor who resigned from Sinn Féin in a dispute over policing, is seeking re-election as an independent.