Sinn Fein Mayor of Derry and Strabane Council Maoliosa McHugh has come under fire for addressing a rally supporting a dissident republican while wearing his chain of office.
Tony Taylor has been in jail since March 2016 having previously been released on licence under the terms of the Good Friday Agreement.
He had been sentenced to 18 years in jail in 1994 for planting an IRA bomb in Londonderry.
He was also jailed for three years in 2011 for possession of a rifle.
Taylor was released from Maghaberry Prison in 2014, but two years later the then Secretary of State, Theresa Villiers, revoked his licence "because of the risk he poses to the public".
No formal charges were laid against him.
DUP councillor Graham Warke was on Derry's Walls observing Sunday's rally.
He accused the mayor of breaching protocol by wearing his chain of office at a political event which he was attending in a private capacity.
This is not the first time Mr McHugh has been criticised for wearing his official chain inappropriately.
He was also seen at a celebration rally at Free Derry Corner when Elisha McCallion won the Westminster election for Foyle last month.
Mr Warke told the Belfast Telegraph: "I was on the Derry Walls at the same time as this rally was taking place.
"I saw the mayor address the rally with his chain of office on which caused me great concern.
"I checked on his calendar if this was an official engagement and it wasn't in his diary, so I can only guess he was there in a private capacity which he is entitled to do.
"What he should not do is wear his chain of office at an event that is highly political.
"Tony Taylor is a convicted terrorist and a dissident republican, and Councillor McHugh is causing offence to the unionist community by wearing his chain of office at a rally supporting such a man.
"As mayor, Councillor McHugh is suppose to represent both communities and adopt a neutral position on any event of a strongly political nature which this rally certainly was.
"It seems that just a few weeks into his term as mayor, Councillor McHugh has gone out of his way to cause offence to the unionist community.
"He also wore his chain of office at a rally held at Free Derry Corner for Elisha McCallion when she won the Westminster election.
"He was certainly not on council business then.
"Councillor McHugh needs to remember he is representing both communities.
"He would do well to look at the example shown by his predecessor, Hilary McClintock."
Last year, councillors voted to support a motion calling for Taylor to be freed.
The mayor has defended his actions at Sunday's rally for Mr Taylor, saying his attendance was in line with council's policy on the campaign.
"I don't think there are just two communities in the council area, I think there are many communities in the council area in the first instance," he said.
"All I am going to say about this is there is a corporate position as far as Tony Taylor is concerned and I was reflecting the corporate position of the council as mayor.
"The council supports the campaign for Tony Taylor to be released and I was there in that capacity."