Veteran socialist Eamonn McCann has said he is resigning as a Derry City and Strabane councillor on health grounds.
In a statement, the People Before Profit councillor said he has developed a neurological condition Ataxia after being diagnosed with epilepsy 15 years ago.
He said he had not found his epilepsy diagnosis disabling in his work as a councillor but said his neurological condition had made it "increasingly difficult" to fulfil his duties towards his constituents.
"I have made my intention known to my party, People Before Profit, and have asked the party to set in motion the procedure for selecting a new councillor in my place," he said in a statement on Monday evening.
"I thank all those who voted for me in the last council election in 2019. I have done my best to deliver on the mandate given to me."
Mr McCann (77) became well-known for his work at forefront of the civil rights movement in Northern Ireland and stood for Assembly election unsuccessfully for more than five decades.
In March 2016, he was eventually elected in March 2016 at the age of 73 to the Stormont Assembly before losing his seat the next year as the result of a snap election.
He returned to politics in April 2019 when he was elected to Derry City and Strabane District Council.
Mr McCann said his party's performance in the Northern Ireland council elections showed that there is an appetite for politicians who want to represent "the interests of all the people at the bottom of society".
In his statement, Mr McCann also thanked his fellow councillors and council staff, adding that it has been "a privilege to represent the Moor DEA, where I was born and reared".
"I have confidence that PBP will nominate a diligent and efficient councillor in my place and that she or he, alongside Shaun [Harkin], will continue to serve the interests of the people of the Moor and contribute to the struggle against oppression and against capitalism, the never-ending source of all our political ills."