Peter Robinson has said the DUP will take part in multiparty talks at Stormont on Monday to resolve the political crisis threatening devolved government in Northern Ireland.

This comes after Northern Secretary of State Theresa Villiers revealed the British government had commissioned an independent assessment of paramilitary organisations and criminality, following the murder of former IRA member Kevin McGuigan in Belfast last month.

A “factual assessment” to be carried out by three individuals, yet to be appointed, will be published by mid-October to inform the five main parties’ discussions and conclusions of the multi-party talks, Ms Villiers said.

Ms Villiers is also establishing a fund to “tackle links between paramilitary organisations and organised crime”.

Mr Robinson told reporters on Friday Theresa Villiers has taken DUP concerns seriously, and the new body the British government is setting up to review paramilitary activity and criminality will provide up to date assessment of each of the paramilitary organisations.

He said it was important “nothing in review impinges on criminal investigations”.

On the three appointments to the assessment panel Mr Robinson said they need to be people with “experience, security clearance and respect to validly carry out the work”.

Sinn Féin’s Martin McGuinness said he was pleased all-party talks will begin on Monday and said Sinn Féin will be entering them as a party “totally and absolutely committed to a peaceful and democratic way of moving forward”.

The Deputy First Minister suggested talks will tackle “big issues” around implementation of the Stormont House Agreement, protecting the disadvantages and vulnerable, ensuring a “workable budget” for government in the North, and “workable institutions”.

On Friday, Mr McGuinness told reporters Stormont had a collective responsibility “to stand together against criminality, violence and the existence of all armed groups”.

On the prospect of the assessment commissioned by the British government concluding that the IRA and some structures exist, as the PSNI Chief Constable concluded following the murder of Kevin McGuigan last month, the Sinn Féin politician said it was a “one-off situation”.

“If we end up in a situation where the body comes forward with the report that creates further problems for the process, then it will all have been a waste of time,” he added. “I don’t think that is going to happen.

“My sense of it is that whatever happens over the course of the next while will depend upon our ability to get the Stormont House Agreement agreed within the negotiations, find a way forward on how we collectively, all of us, bear down on criminality and violence and armed groups, wherever they come from.”

Earlier, Mr Robinson had said until resolution is found it will not be business as usual for the DUP at Stormont.

He had stepped aside from his role as First Minister and withdrew his ministers from government, except for Arlene Foster, who will continue as Finance Minister and Acting First Minister.

Mr Robinson said: “Following the chief constable’s assessment of those involved in the murder of Kevin McGuigan, the party said that it would not be business as usual.

“We insisted to the government that there were two issues that needed to be addressed if devolution was to continue. Those issues were the full implementation of the Stormont House Agreement and dealing with all paramilitary structures. The party said it would not engage in knee jerk reactions but rather would deal with the outstanding issues in a strategic manner.”

Mr Robinson described the statement by secretary of state Theresa Villiers on Friday as “a welcome first step in demonstrating that the government are taking our concerns seriously”.

“We recognise the secretary of state is now taking action to address the two concerns we had raised. We have consistently argued that ultimately the business of determining the long-term steps to address paramilitary links must be addressed and resolved through the talks.

“On the basis of the secretary of state’s statement today we will be participating in the talks on Monday.

“I am not in the business of wrecking devolution. I want to see good, effective government in Northern Ireland. Whilst others may be focused on process this party is focused on getting the right outcome. Our objective for the talks is to see the full implementation of the Stormont House Agreement and a mechanism to put all those engaged in terrorism and criminality out of business once and for all.”

Deputy First Minister, Sinn Féin’s Martin McGuinness welcomed the news on Twitter.

“Pleased that Unionist leaders will be present for vital inclusive talks on Monday. #Peace,” he wrote.

In a statement Martin McGuinness said: “Sinn Féin is committed to pursuing our goals through peaceful and democratic means and is entering these talks on the firm and sole basis of our electoral mandate.

“We have a burning duty to achieve a resolution to the outstanding issues from Stormont House and other agreements and a workable budget, which enables the Assembly to protect public services and grow the economy.

“We will work with the other parties to tackle the issue of armed groups, which want to drag us back to the past including active unionist paramilitaries and armed republican dissidents, and organised criminals who are a blight on the community.”

Ulster Unionist leader Mike Nesbitt also welcomed the announcement by Theresa Villiers

but stopped short of confirming his party would be in talks.

“I’ll speak to the party executive this afternoon and reflect on where we go from here.”

PSNI chief constable George Hamilton said it will provide “full co-operation and support to all the measures that have been outlined” by Theresa Villiers.

“Organised crime has a disproportionate effect on our most vulnerable communities and we welcome the clear focus on this issue,” he added.

“PSNI will continue to build on our work with the organised crime taskforce, an Garda Síochána and our other partner agencies to tackle organised criminality.

“We welcome the independently reviewed assessment of paramilitary organisations announced by the secretary of state and PSNI will play our part in assisting in this process.”

In a statement issued by Minister for Foreign Affairs Charlie Flanagan said the British government’s assessment of paramilitarism is a “once-off exercise” that will be completed “over the coming weeks”. The assessment, he said, “is intended to assist the parties in the talks in their collective consideration of how the impact and legacy of paramilitary activity should best be addressed”.

“It does not pre-empt the question of possible future monitoring arrangements which will be a matter for consideration and agreement in the talks.”

He described the functioning of the devolved institutions in Northern Ireland as “increasingly precarious”.

“ Time is running out for the critical issues to be resolved and collapse of the Executive and Assembly averted. It is therefore imperative that the all-party talks now resume. After ten days of shadow-boxing, it is essential that all of the five main parties in Northern Ireland, with the support of the two Governments, urgently get down to the serious business of fully implementing the Stormont House Agreement and addressing the impact and legacy of continuing paramilitary activity. I look forward to these talks resuming on Monday and making rapid progress.”