PSNI have confirmed the unconditional release of 59-year-old Sinn Féin politician and former IRA member Bobby Storey has been released unconditionally.

Storey was arrested on yesterday in connection with the murder of Kevin McGuigan in Belfast.

His lawyer John Finucane said on Twitter his client would be suing for unlawful arrest:

After 2 days in Antrim my client Bobby Storey has been freed. No evidence was put at any stage & my client will be suing for unlawful arrest

— John Finucane (@johnfinucane) September 10, 2015

In a statement, Sinn Féin leader Gerry Adams underlined his concern at the train of events that has followed the murder of McGuigan:

"The unconditional release of Bobby Storey underlines the contrived nature of the current crisis in the political institutions in the North.

"I want to reiterate my grave concern about the nature in which the murder of two men has been exploited and also at the way the current difficulties have developed in the last few weeks, including the arrest of Bobby Storey."

The PSNI has also confirmed the unconditional release of a 45-year-old man, believed to be Eddie Copeland, and a 58-year-old man, believed to be Brian Gillen, this evening. 17 people have been arrested so far in relation to the killing, though none yet charged.

Only a 50-year-old woman arrested this morning remains in custody.

Robinson steps aside as First Minister

Peter Robinson has announced he will stand aside as First Minister of the Northern Irish Assembly.

Robinson also confirmed the resignation of all the party's ministers from the Stormont Assembly, with the exception of Arlene Foster, who will remain in her post as Minister for Finance and acting First Minister.

The continuing presence of a DUP member on the executive means the devolved government will not collapse as feared. However there is only one week left for talks to save the collapse of the Assembly and the triggering of elections.

The party leader explained his position in a statement:

"The failure of the SDLP and Sinn Féin to implement the Stormont House Agreement together with the assessment from the Chief Constable of the involvement of IRA members in murder, the continued existence of the IRA and the arrests that followed has pushed devolution to the brink.

"Yesterday I indicated that we would ask the Business Committee to adjourn Assembly proceedings to allow negotiations to take place.

"That proposal did not find sufficient support. The Government can still legislate to suspend the Assembly and allow space for the parties to negotiate."

He also said Foster has remained in her psoition "to ensure that nationalists and republicans are not able to take financial and other decisions that may be detrimental to Northern Ireland."

Peter Robinson says it's no longer business as usual in the executive: 

The announcement came after a DUP proposal to adjourn the Northern Ireland Assembly was rejected by other parties. The UUP, SDLP and Sinn Féin all opposed the move.

Sinn Féin leader Gerry Adams is calling for calm: 

Taoiseach Enda Kenny tonight appealed to the parties in Northern Ireland to accept their responsibility and save the Stormont institutions. 

Addressing the Fine Gael Parliamentary Party in Adare, Limerick tonight, Enda Kenny appealed for the political parties to come back from the brink: 

Irish Foreign minister Charlie Flanagan has expressed deep concern at the DUP's decision:

"Following today's serious developments, the power-sharing institutions are on the edge of the precipice," he said in a statement.

"I urge Northern Ireland's political leaders to take a step back and consider the gains achieved over recent years, the benefits to the people of Northern Ireland and what is now at stake."

Yesterday, Robinson said he and his DUP ministers will resign if the assembly is not suspended.

It follows allegations by the PSNI that the IRA was involved in the murder of Mc Guigan, which Robinson called "unacceptable."

SDLP leader Alasdair McDonnell announcement he would not support an adjournment following a meeting at Stormont this afternoon.

Earlier Sinn Féin's Mary Lou McDonald said the meeting between the Taoiseach and McDonnell was a mistake.

But Tánaiste Joan Burton hit back - saying stability in the North is too important not to be involved.