Speaking in Londonderry, Ms Harney said it was also her view no one could be involved in the process if they were not totally committed to peaceful and democratic politics.

BBC: PMs discuss NI peace process

"Polyamorous relationships tend to be ongoing, sustainable, emotionally bonded, committed relationships with more than one person, with the knowledge and consent of everyone involved, " says Anita Wagner, who says she has been in polyamorous relationships on and off for the last 15 years.

BBC: Is it possible to have a happy open marriage?