Democratic Unionist Ministers who resigned from the Stormont Executive in the wake of an IRA linked murder are to return to office following the publication of a Government ordered review of paramilitaries activities.

The independent assessment found that all the main republican and loyalist groups, including the Provisional IRA, still exist, but their leaders are committed to peace.

The review, ordered after the shooting of ex-IRA man Kevin McGuigan in August, said an IRA "Provisional Army Council" remains in place, and IRA members believe that ruling body "oversees" Sinn Fein's strategy.

DUP First Minister Peter Robinson stood aside from his duties last month at the height of the political crisis, and three of the party's four other Executive ministers resigned.

The party has faced intense criticism since, as ministers have been reappointed for a matter of hours, only to resign again in a repeating cycle - in order to prevent other parties taking the posts.

The party said it was now prepared to re-appoint all its ministers to office.

Sinn Fein has rejected the claim that an IRA council tells it what to do. 

Sinn Fein's deputy first minister at Stormont Martin McGuinness insisted his party was the "only organisation" that represented the mainstream republican movement.

"As far as I am concerned Sinn Fein is the only republican organisation involved in the peace process, in democratic politics and in political activism," he said. "We take instructions from no one else."

The DUP said the report "sets the agenda" in regard to on-going talks involving the five main Stormont parties and the UK and Irish governments.

The party's ministers resigned when Sinn Fein's northern chairman Bobby Storey was arrested by detectives investigating the McGuigan murder. Mr Storey, who vehemently denied involvement, was later released without charge.

The number of DUP ministers out of office increased from three to four in the midst of the crisis as the party took over a post vacated when the Ulster Unionists walked out of the administration outright.

Northern Ireland Secretary Theresa Villiers outlined the paramilitary report's findings to Parliament.

It found that all the main paramilitary groups had committed murders since the ceasefires of the 1990s but stressed that they were not engaged in or planning terrorist activities.

In regard to the IRA, the three-member independent panel which assessed police and security service intelligence, found that "the structures of PIRA remain in existence in a much reduced form".

These structures include "a senior leadership, the 'Provisional Army Council' and some 'departments'," the report said.

The panel did not think the IRA is actively recruiting or rearming.

The report stated that IRA members believe the Army Council "oversees both PIRA and Sinn Fein with an overarching strategy".

However, it said this strategy has a "wholly political focus".

The report said: "The PIRA of the Troubles era is well beyond recall.

"It is our firm assessment that PIRA's leadership remains committed to the peace process and its aim of achieving a united Ireland by political means.

"The group is not involved in targeting or conducting terrorist attacks against the state".

The DUP said it accepted the "entirety" of the report's findings, describing them as "frank and informative".

A party statement added: "The report might clear the republican leadership in that it reaches a 'firm conclusion that it is committed to the peace process' and that 'it has a wholly political focus' but it makes depressing reading about the pace of change within the organisation and the level of control the leadership has over some of its members and their activities.

"In truth it demonstrates the scale of the task we all face in normalising our society and making the Assembly sustainable.

"While the report indicates that IRA structures remain in existence it states it is in a much reduced form and the IRA of the Troubles era is well beyond recall. The factual assessment finds that the remaining organisation is not involved in any targeting, recruiting, arms procurement, planning or conducting terrorist activities as had been the case previously. Yet the idea that any paramilitary structure still exists is unacceptable. This is true of loyalist groups as much as republican ones."

The DUP said it was "disturbed but not surprised" that an IRA Army Council still existed.

The party said the report confirmed the assessment of Northern Ireland's police chief George Hamilton in August that individual members of the IRA were involved in the McGuigan murder but the leadership did not sanction it and was wedded to peace.

It suggested the subsequent arrest of Mr Storey had confused the picture.

"We sought an up to date assessment by the PSNI and security services to inform our future decisions," said the party statement.

"That is now available to us. It confirms the Chief Constable's August statement rather than the contradictory implications that flowed from the arrest of Bobby Storey and on that basis Ministers will be appointed to office later today.

"However the report sets out very starkly the issues that the talks process must deal with. Any agreement flowing from these talks must include proposals to tackle the matters identified in the review. We have a very short time to reach agreement and while some common ground has been evident all the parties must step up the pace in the next few days. This report has brought clarity to this key issue."

The three members of the panel asked to conduct the exercise were former independent reviewer of UK terror laws Lord Carlile of Berriew; Rosalie Flanagan, a former permanent secretary at Stormont's Department of Culture, Arts and Leisure; and Northern Ireland-based QC Stephen Shaw.

Mr McGuigan was shot dead in Belfast in August in a suspected revenge attack for the murder of former IRA commander Gerard "Jock" Davison, 47, three months earlier.

Detectives believe some of Mr Davison's associates suspected Mr McGuigan of involvement in his shooting.

Before the McGuigan murder, the future viability of the administration had already been in doubt as a consequence of long-standing budgetary disputes, with the row over the non-implementation of the UK Government's welfare reforms the most vexed.