Monica McWilliams from the Independent Reporting Commission (IRC) told BBC Radio Ulster’s Evening Extra programme that unless an independent expert makes the assessment “then we will be exactly in the same place in 10 years’ time”.

Ms McWilliams said she “can understand” how Long “thinks that this won’t work”, but added that “doing nothing isn’t an option”.

“Our understanding is that there is an appetite amongst Republicans and Loyalists to move off the scene.”

Ms McWilliams said the scoping exercise “is going to be evidence based, the groups themselves are going to have to volunteer no one is going to impose it”.

She added that in the IRC report there is seven different criteria, and groups will be judged on that, as part of the independent expert’s work.

Ms McWilliams said a report will be then be produced by the expert for the UK and Irish governments in a year’s time.

“We will be in a much better place in a years time knowing exactly who is doing what and the ‘clear blue water’ that Naomi talks about will then be in place.”

The IRC’s latest report was published on Tuesday – it described the appointment as “a vital step in the journey towards completing the goal of ending paramilitarism in Northern Ireland once and for all”.

Multiple republican and loyalist organisations remain active almost 30 years after the Good Friday Agreement.

Dissident republican groups, such as the New IRA, who oppose the peace deal, continue to target police officers.

Also, groups aligned to the Irish National Liberation Army (INLA), the Ulster Volunteer Force (UVF) and Ulster Defence Association (UDA) are heavily involved in criminality.