Supporters of dissident republicans need to "get real" and realise they are a "ragbag" of criminals out for their own ends, Martin McGuinness has warned.
In an impassioned attack on the extremists who murdered prison officer David Black, Stormont's Deputy First Minister said they swim "in a sea of criminality and drugs" while wrapping themselves in a flag of political convenience.
The Sinn Fein veteran and First Minister Peter Robinson stood shoulder to shoulder with Irish prime minister Taoiseach Enda Kenny and his deputy Tanaiste Eamon Gilmore after a meeting in Armagh as they jointly denounced the killing.
Mr McGuinness said there was no evidence the dissident movement was growing but he had a stark message for the "tiny" minority who supported their actions.
"What you have to understand is that if you support these people, you are effectively supporting people who are swimming in a sea of criminality and drugs, dressing it up on occasions in a flag of political convenience and you shouldn't be under any illusions about that," he said.
Away from attacks on security force personnel, dissidents have become embroiled in violent feuds with drug dealers on both sides of the Irish border, resulting in a number of recent murders.
"People need to get real," Mr McGuinness said. "They need to recognise the danger that a tiny number of people can represent to human beings and they need to recognise that the world has changed, that over the course of the last 15 years we have built something, all of us together, which we can be very proud of.
"And we are not going to let it go, to anybody, certainly not to a ragbag of people who have inspired themselves and others for their own purposes, to fill their own coffers, to engage in criminality and to extort money from drug pushers and drug barons - effectively becoming themselves part of the drug problem on the island of Ireland. That message needs to go out very loud and clear."
Mr McGuinness said people could not be "half baked" in their response to the murder and had to wholeheartedly support the authorities in tracking down Mr Black's killers.
At the close of the scheduled North South Ministerial Council meeting, Mr Kenny was equally scathing about the hardliners. "Yvonne Black has lost a husband, her children Kyle and Kyra have lost a father and Northern Ireland has lost a good hard-working son," he said. "We condemn this murder unreservedly and the Tanaiste and I have pledged full support, full information and full response to the authorities in Northern Ireland and the PSNI."