There are between 1,000 and 1,500 active volunteers in the Provisional IRA, Minister for Justice Michael McDowell estimated.
None of the dissident groups would have many more than 150 people attached to them, he added.
Mr McDowell said there were reasons to believe that the Provos were engaged in a process of consultation on how the entire movement, IRA and Sinn Féin, were going to address the new situation created by the political circumstances in the North - the fact that they were discovered to be the masterminds and perpetrators of the Northern Bank robbery, money laundering in the South and the involvement of their members on the murder of Robert McCartney.
"I believe that those consultations are at advanced stage and it is now a matter for the leadership of the provisional movement to decide when they will announce an end to paramilitary activity, criminality, violence, the threat of violence and their reign of terror in nationalist areas of Northern Ireland."
Other groups were continuing to attempt to get their acts together, said Mr McDowell. "The Garda continues to have considerable success in breaking up their efforts and detecting their activities. With regard to freelance activities, there is some sporadic evidence that former paramilitaries are now turning to ordinary criminality as a lifestyle-maintenance activity outside their paramilitary connections."
Recently, he added, a number of incidents had taken place in which those kinds of people, apparently acting for their own personal gain, had become involved.
Asked by Fine Gael justice spokesman Jim O'Keeffe about a timeframe for a decision by the Provisional IRA, Mr McDowell said the sooner decisions were made the better.
"However, they have to be made in a credible way and be accompanied by acts. The Taoiseach made it clear to the provisional movement that words alone will not suffice. They have to be accompanied by acts and inaction of a palpable kind which will convince, not only the members of those movements, but also the community at large and, in particular, the community which has most to fear from them that is well and truly over."
Mr McDowell said the Independent Monitoring Commission (IMC) had concluded that the Provisional IRA remained a highly active organisation, which was at present determined to maintain its effectiveness in terms of organised crime and the potential for terrorism.
The commission, he said, had stated that the Real IRA was the most active of the dissident republican groups and remained engaged in acts of terrorism and organised crime. "The IMC goes on to state that the Real IRA had recruited and trained members in the use of firearms and had continued to improve its capacity in the use of explosives. The IMC believes that this is the work of an organisation which is ruthless and committed to terrorism."
He was assured by the authorities that the Garda had sufficient resources to deal with the terrorist and criminal activities of paramilitary groups. The Garda had never been better resourced, with the Government increasing its budget from €599 million in 1997 to €1.39 billion in 2005.
