The vice-chair of last month's talks on the contentious issues of the past in Northern Ireland has said failure to agree a way forward will represent a significant missed opportunity.

Professor Meghan O'Sullivan was part of the team lead by Dr Richard Haass that put forward proposals which failed to get the agreement of all of the five main parties at Stormont.

Prof O'Sullivan told RTÉ's Prime Time that the stalemate could fuel further protests and social unrest.

She said: "If there isn't movement on these three issues in the way that we've put forward or another way, it will be a major loss for Northern Ireland.

"These three issues: the past, flags and emblems and issues of identity, and parades. These are all things that still divide Northern Ireland, really bog down that society and prevent it being a prosperous and free, in the broad sense of the word, society."

Prof O’Sullivan went on to say: "There could be an even darker downside. Which is the fact we've seen issues around parades and flags lead to political and social unrest, and even violence in some cases.

"And a conditioned stagnation or stalemate on these issues could fuel more protests and could fuel rejectionists on both sides of the spectrum."