Taoiseach Brian Cowen has expressed “deep sadness and disgust” at the murder of a PSNI officer “as he was doing his duty in serving the community in Craigavon”.
“As with the murders in Antrim, this callous crime is an attack on the Irish people and the peace we have all worked so hard for,” Mr Cowen said in a statement early this morning.
“The people and all of their democratic representatives reject this violence and will overcome the evil and unrepresentative minority who want to drag us back to the past.
“Violence and hatred will not triumph over peace and democracy. This is a time of sadness but also of solidarity."
President Mary McAleese said dissident republicans must not be allowed to succeed.
"The dissidents are now a tiny, isolated band of throwbacks, using tired, old, failed strategies," she said. "They must not and will not be allowed to succeed. The answer to them has to be to keep on building a just peace and to see to it that the perpetrators are brought to justice.
"I hope those who know them will reflect on what is at stake here and be persuaded by the massive public and political solidarity which has greeted the cowardly acts at Massareene and now Craigavon to lift the phone, tell the police, join the peacemakers and put an end to this hell on earth."
Minister for Justice Dermot Ahern said dissidents were unwittingly wrecking their goal of a united Ireland.
“When Northern Ireland was de-militarised, it was a normal society. We don’t want to go back,” he said.
“What paramilitaries have done for 40 years in the name of Ireland has been to militarise that part of Ireland and put whatever unity of the island further and further away.”
Minister for Foreign Affairs Micheal Martin branded the latest attack as “callous and cowardly” and said it caused revulsion among all right-thinking people.
“The perpetrators of this attack, and of the murders in Antrim town on Saturday, are clearly intent on plunging Northern Ireland back into conflict and destroying the peace settlement endorsed by the people of this island.
“Those who carry out such acts received a clear and simple message from the elected representatives of all the people of Northern Ireland in the Assembly yesterday morning — you have no support and you will not succeed.”
Mr Martin, who is due to hold talks with the Northern Ireland Secretary of State in coming days, said the Irish and UK governments will continue to cooperate closely in countering the threat from dissidents.
Fine Gael leader Enda Kenny said last night’s killing was a despicable outrage by a tiny minority which is determined to destroy civil society.
“This minuscule group of people cannot and will not be allowed to destroy the peace that everyone in society benefits from,” he added.
“Fine Gael will support the Governments and policing authorities in all their efforts to bring these killers to justice.”
Labour leader Eamon Gilmore said the murders in Antrim and Craigavon were "an assault on democratic principles and must not be allowed to succeed.
“All democrats, North and South, nationalist, unionist and other, must stand together in the face of these attacks and ensure that this tiny and unrepresentative minority are not allowed to usurp the will of the overwhelming majority on people on this island," he said.