Sinn Fein councillors voted against former Deputy First Minister Seamus Mallon being granted the Freedom of Drogheda because they thought it was "wrong to elevate only one person involved in the peace process".
Drogheda Sinn Fein councillor Joanna Byrne spoke out after she and party colleagues Kenneth Flood and David Saurin opposed the motion.
Mr Mallon (81, right) was involved in the civil rights movement during the Sixties and served as the deputy leader of the SDLP from 1979 to 2001. He was also Stormont's Deputy First Minister from 1998 to 2001.
Mr Mallon is one of the architects of the Good Friday Agreement, having helped broker the 1998 accord, and will be awarded the Freedom of the Borough of Drogheda on June 8.
At Monday's meeting of Louth County Council, Deputy Mayor Richie Culhane read out a statement in the absence of Mayor Pio Smith.
It reportedly said: "I am happy to offer the Freedom of Drogheda to Seamus Mallon as I believe that he is a patriot in the true sense of the word and has worked to unite Protestant, Catholic and dissenter like a true republican.
"Mallon was a straight talker and his goal in politics and life was to progress society in a manner that benefited all.
"Having a go at other political parties or communities for the sake of it was not his style. Instead, he tackled issues like inequality, Irish unity, lack of housing and unemployment, and he did this for both Catholic and Protestant.
"All people who live on the island of Ireland owe Seamus Mallon a deep debt of gratitude for the significant role he played in engendering hope in a time of despair and in helping to create new and better inter communal relationships on this island."
However, Ms Byrne told the Belfast Telegraph that she and her party colleagues "didn't feel it was right" to honour Mr Mallon in this way.
"From a Sinn Fein perspective, we thought it was wrong to elevate only one person involved n the peace process," she said. "If you are going to acknowledge one, acknowledge them all. "We didn't feel it was right.
"Plenty of people played their part in civil rights and ensuring peace on this island.
"We didn't sound our opinion, and we didn't say anything negative.
"I understand that the Freedom of the Borough is usually given to one person."
SDLP Newry and Armagh MLA Justin McNulty welcomed the honour for Mr Mallon.
"I welcome the move by Mayor Pio Smith, offering Seamus Mallon freedom of Drogheda," Mr McNulty said. "It is however disappointing to see Sinn Fein vote this motion down.
"Seamus Mallon was a key player in bringing peace to the North.
"It is only right that he be honoured in this way.
"As the former MLA for my own constituency of Newry and Armagh, it fills me with much pride but, more importantly, hope that the politics of the SDLP is recognised and the sacrifice of our leaders remembered."
Other dignitaries to receive the freedom of Drogheda include Nobel Peace Prize winner John Hume and Pope John Paul II.