Sinn Féin has rejected former SDLP deputy leader Seamus Mallon's claim that republicans have failed to understand the essence of the Good Friday Agreement.
The former Newry and Armagh MP, who was appointed deputy first minister after the signing of the 1998 accord, said the DUP and Sinn Féin had failed to implement the spirit of the agreement.
He said Stormont's two biggest parties had tried to change the Good Friday Agreement and he accused both of creating a mess by failing to strike a deal in the last round of negotiations.
Mr Mallon (80) was speaking on Monday at the John Hewitt International Summer School in Armagh.
He said the "very essence" of the Good Friday Agreement had been damaged by a failure to reconcile unionists and nationalists.
"In 12 years, neither of the two parties which were in charge – and in case there’s any doubt about it, the DUP and Sinn Féin – not one scrap of proper proposals were made in relation to how we as people can live better together," he said.
"They haven’t done it – and that was the whole essence of the Good Friday Agreement."
The former deputy first minister said a "sick society" defined bonfires as culture, while "the other side" used the Irish language for what he described as a "patently political reason".
"When you start to make a cultural element a red line in terms of political negotiation, it is impossible to pursue that without turning that into a political cudgel," he said.
But Sinn Féin MP Chris Hazzard rejected Mr Mallon's accusations.
"The difficulties we face stem from the fact that the DUP have endorsed the structures of the Good Friday Agreement but not the substance of it," he said.
"That needs to change because language rights, equal marriage and the right to coroners’ inquests should be protected in law as they are everywhere else on these islands – they are rights, not red lines and Sinn Féin will continue to pursue those rights when the talks resume."
The South Down MP said his party's consistent position was that the Good Friday Agreement and subsequent agreements must be fully implemented.
