Presbyterian minister David Latimer has appealed for people in Northern Ireland to work together before it is too late.
Political powersharing at Stormont collapsed earlier this year after the Democratic Unionists fell out over a botched green energy scheme which is predicted to massively over-spend.
The Rev Latimer, from First Derry Presbyterian Church, attended the funeral of Brendan Duddy at St Eugene's Cathedral in Londonderry and paid public tribute to his peacemaking efforts.
He added: "We have suffered together and felt pain together, we now need to move forward together - for we all belong to this place.
"There can be no going back because we have come too far. Work together before it is too late."
During the Troubles, First Derry was frequently a target for attack; sometimes missiles were launched from the other side of Derry's historic walls and paint bombs thrown.
Mr Latimer has been a conciliatory figure in a largely nationalist area and has spoken openly about his friendship with late Sinn Fein leader Martin McGuinness.