The importance of arms decommissioning in the implementation of the Belfast Agreement was stressed by the Taoiseach during a series of statements on Northern Ireland.

Decommissioning, said Mr Ahern, had been acknowledged to be essential.

"It has been left to the last. Implementing this part of the agreement cannot reasonably be interpreted by anyone as a verdict on the conflict of the last 30 years or as changing its outcome.

"As I have said, everyone will already have their own strongly held opinions on the Troubles that are unlikely to change. Decommissioning is a necessary contribution to the consolidation of peace and democracy and to the creation of trust. It will provide the conditions that will lead to a genuine all-round demilitarisation of Northern Ireland.

"But it should also be clearly understood that just as decommissioning is a voluntary act, so also is a willingness by any party to serve or go on serving with others in government. The work of Gen de Chastelain and the independent commission remains central to resolving the whole problem satisfactorily."

Mr Ahern issued a warning to any "sinister forces" waiting tactically for the most propitious moment to try and destroy the work of the agreement.

"This Government and this House, representing the Irish people, will not tolerate any paramilitary attack by dissident organisations. We are determined that they will, for all practical purposes, be dissolved and disarmed, if they will not voluntarily do that themselves.

"There is no vestige of an excuse today for any organisation that would call itself republican to repudiate or deny the living democracy that now exists in Ireland, both North and South."

Mr Ahern praised all those involved in the implementation of the agreement, adding that although some deputies might find it strange to hear him saying it, he was glad the DUP had taken up its positions on the Executive.

It had been a very human sight to see the new DUP ministers being congratulated by their family and friends, he said.

"Far be it for me to suggest a theme for a sermon to the leader who visited me in Government Buildings as head of the Free Presbyterian Church in Ulster a few weeks ago.

"But, when we listen at Christmas to the prophet who foresees that `the wolf also shall dwell with the lamb' and that `they shall not hurt nor destroy in all my holy mountain', we will surely think of Northern Ireland." Mr Ahern said in the good atmosphere created by recent developments, they should not ignore the importance of continuing the implementation of other parts of the agreement, especially those relating to justice, security and human rights matters, which remained the responsibility of the two governments.

"I attach particular importance to the full implementation without delay of the Patten report, which arbitrates fairly between widely differing conceptions about the future of policing.

"It is of vital importance to the future that young people from the nationalist community be encouraged by changes that are also symbolically reflected to join in a new beginning to policing, so that the change is felt as soon as possible on the ground.

"The past services of the RUC have been properly recognised, but they, as the parties in the Assembly have had to do, need to accept their part in the radical changes in governance required by the Good Friday agreement."

Mr Ahern said the new Articles 2 and 3 encapsulated a modern understanding of constitutional republicanism. "The last traces of irredentism are gone. The nation is defined in the most open, inclusive and pluralist manner possible, without coercion. Any North-South discrimination in relation to the obtaining of passports will be abolished under the new Nationality and Citizenship Bill. "The whole tenor of the Articles will put a new emphasis on civic society, as one of the pillars underpinninng the State, alongside the cultural nationalism expressed in Article 1 and at the end of Article 2 in relation to the Diaspora. Irish people and people of Irish descent living abroad have expressed appreciation of the recognition of their identity and affinity to this country afforded in the last sentence of Article 2."

The Articles were irrevocable, said Mr Ahern.

"They express the spirit of Ireland today, and the conditionality of their implementation is now terminated. I could not envisage a situation even where the functions of the agreement had been interrupted for a considerable time, that the parties in this House or the people would wish to revert to the previous wording.

"The old Articles 2 and 3 were put in place as a form of protest against the legitimacy of partition, after all the safeguards of the 1920-21 settlement had been cast aside.

"They have been replaced, like the Government of Ireland Act 1920, by a constructive and more explicitly democratic method of uniting the country, should the conditions for this exist. All sides have had to take risks for peace. This is the risk that we are taking."

The Fine Gael leader, Mr John Bruton, said no political party should allow itself to get hung up on the issue of whether steps required under the Belfast Agreement were voluntary or taken under pressure.

"All steps taken under the agreement are essentially voluntary. No one was forced to sign up to it, but equally, all steps by all parties are taken under some degree of pressure in that each knows that if it does not play its part, others will not play theirs.

"The decommissioning of weapons has been part of the talks process, and of the agreement arising from it, from the very beginning. Decommissioning will be voluntary in all cases, but also it must occur if the agreement is to be fulfilled.

"At this stage, we are advanced enough not to allow considerations of face to prevent us from doing what needs to be done. There are no preconditions any more, but everything in the agreement is conditional on everybody meeting their obligations.

"It has been central to the agreement that any participant can withdraw from it at any time. There is nothing new about that, but equally each participant knows the consequences of such an act."

The Labour leader, Mr Ruairi Quinn, said there were grounds for optimism that progress would be made.

"The expected appointment by the IRA of an interlocutor will be a huge step forward. Thankfully, Northern Ireland is now enjoying the most peaceful period it has experienced since 1968. The number of punishment attacks has declined dramatically. There have been close to six months without a politically motivated murder in Northern Ireland.

"Vigilance and care continue to be required. It is, of course, an imperfect peace, but can anyone honestly look at the situation in any of the 30 years that preceded the Good Friday agreement and say that it was better then than it is now?"

Mr Quinn said there had been many dark days in Northern Ireland over the past three decades - Bloody Sunday, Bloody Friday, La Mons, the Droppin' Well, Enniskillen, Greysteel, Loughin island.

The Minister for Justice, Mr O'Donoghue, said not everyone was happy with present developments at both ends of the political spectrum, which was as it should be in democratic societies. "But I want simply to say this to the small number of people who might be tempted to use violence to thwart the will of the vast majority of the people of this island: the full resources of the State will be used against you and you will not succeed."