Fianna Fail leader Micheal Martin has urged the British and Irish governments to directly intervene in the Stormont power-sharing executive.
Furthermore, he has called for an overhaul in the North-South bodies set up under the Good Friday Agreement.
Speaking at his party’s annual commemoration of the 1916 Easter Rising, Mr Martin attacked the DUP/Sinn Fein-led adminstration for wreaking “immense damage” on Northern Ireland’s post-peace process institutions.
“We need direct engagement by both the Irish and British governments to end the stranglehold in Stormont by two parties,” he said.
“This is doing immense damage to public support for the institutions and public engagement in politics.”
Mr Martin has previously accused the DUP and Sinn Fein of pandering only to their own communities while failing to build bridges between them.
Pointing out his own party’s “central role” in the 1998 peace accord, Mr Martin said the Good Friday Agreement provided an opportunity to build “not just an absence of war but also lasting reconciliation and development”.
“This opportunity is being wasted,” he said.
“We need a new beginning in the concept of North-South bodies, which have an enormous potential to deliver services and sustained development on both sides of the border.”
The North-South bodies include Waterways Ireland, Food Safety Promotion Board, Trade and Business Development Body (known as InterTrade Ireland), Special EU Programmes Body, North/South Language Body, Foyle Carlingford and Irish Lights Commission and Tourism Ireland.
DUP peer Lord Morrow responded by saying Mr Martin “should leave the politics of Northern Ireland to the people Northern Ireland”.
He said: “This is an internal matter for Northern Ireland. Given the wrangling over a new government in his own country in recent months, I would have though he has enough to worry about in his own backyard.”