Tension has been mounting since the murder of Kevin McGuigan and the subsequent arrest of Bobby Storey, the senior Sinn Fein figure. However, it was comments by the Police Service of Northern Ireland (PSNI) Chief Constable George Hamilton that the IRA was involved in the murder, that has been so politically explosive.
Police believe Mr McGuigan was killed by individual members of the Provisional IRA in revenge for the death of prominent republican Gerard "Jock" Davison in May. However, Sinn Fein has always insisted that the IRA no longer exists and has accused both unionist parties of ramping up the crisis for electoral gain.
— DUP (@duponline) September 9, 2015
My statement announcing the resignation of DUP Ministers: http://t.co/RZyT8SXH0m— Peter Robinson (@DUPleader) September 10, 2015
Now that Robinson and most of his ministers have stepped down, the Northern Ireland Executive — which carries out the work of government in Northern Ireland — is in complete disarray, as trust between the republican and unionist parties has collapsed.
The 1998 Good Friday peace deal ended the so-called Troubles — three decades of tit-for-tat killings between Catholic Irish nationalists, who want the province to unite with Ireland and Protestant unionists, that left 3,600 people dead.
The Northern Ireland Assembly is an uneasy alliance of the main political parties dominated by the Democratic Unionist Party (DUP), the largest unionist political party in Northern Ireland, led by Robinson; Sinn Fein, the Irish republican political party, long associated with the Provisional IRA, led by Gerry Adams; the Social Democratic and Labour Party (SDLP), the social-democratic and Irish nationalist party, led by Alasdair McDonnell MP; the Ulster Unionist Party (UUP), one of the two main unionist political parties, led by Mike Nesbitt; and the Alliance Party of Northern Ireland (APNI), led by David Ford.
The unconditional release of Bobby Storey underlines the contrived nature of the current crisis. http://t.co/kJBfouUHer— Gerry Adams (@GerryAdamsSF) September 10, 2015
Robinson told reporters: "The failure of the SDLP and Sinn Fein to implement the Stormont House Agreement, together with the assessment of the Chief Constable of the involvement of the IRA in murder, the continued existence of IRA structures and the arrests that followed has pushed devolution to the brink.
"In light of the decision by republicans, nationalists and the Ulster Unionist Party to continue with business as usual in the Assembly, I am therefore standing aside as First Minister and other DUP ministers will resign with immediate effect with the exception of my colleague Arlene Foster."
"I have asked Arlene to remain in post as Finance Minister and Acting First Minister to ensure that nationalists and republicans are not able to take financial and other decisions that may be detrimental to Northern Ireland."
His statement was followed by the resignation of Simon Hamilton as Health Minister, Mervyn Storey as Social Development Minister, Jonathan Bell as Enterprise and Industry Minister and junior minister Michelle McIlveen.