As part of the agreement, it was proposed to build on the existing Inter-Parliamentary Commission in English-Irish. Prior to the agreement, the body was composed only of parliamentarians from the British and Irish assemblies. In 2001, as proposed by the agreement, it was extended to include parliamentarians of all members of the Anglo-Irish Council. What complicates matters further is that, at the end of the negotiations on a united Ireland, the implementation of the outcome of the negotiations would require a constitutional amendment in the Republic and, therefore, a new referendum. Issues of sovereignty, civil and cultural rights, dismantling of arms, demilitarization, justice and police were at the heart of the agreement. „At a time of great uncertainty, we believe it is very important that the United States reaffirm its support for the Good Friday Agreement and the Northern Ireland peace process. We recommend that you support Assembly 585 and vote in favour of the resolution when it comes to a final plenary vote. It is not clear what this requirement would meet. The constitutional unit proposes that a coherent majority in opinion polls, a Catholic majority in a census, a nationalist majority in the Northern Ireland Assembly or a majority vote in the Assembly could all be seen as proof of the majority of a unified Ireland.
However, the Secretary of State must ultimately decide whether the condition is met. Direct domination of London ended in Northern Ireland when power was formally transferred to the new Northern Ireland Assembly, the North-South Council and the Anglo-Irish Council when the opening decisions of the Anglo-Irish Agreement came into force on 2 December 1999.    Article 4, paragraph 2 of the Anglo-Irish Agreement (the agreement between the British and Irish governments on the implementation of the Belfast Agreement) required both governments to inquire in writing about compliance with the terms of entry into force of the Anglo-Irish Agreement; The latter is expected to come into effect as soon as both notifications are received.  The British government has agreed to participate in a televised ceremony at Iveagh House in Dublin, the Irish Foreign Office. Peter Mandelson, Minister of Northern Ireland, participated in his participation in early December 2, 1999. He exchanged notifications with David Andrews, the Irish Foreign Secretary. Shortly after the ceremony, at 10:30 a.m., the Taoiseach, Bertie Ahern, signed the declaration of formal amendment of Articles 2 and 3 of the Irish Constitution. He then informed the D`il that the Anglo-Irish agreement had entered into force (including some endorsements to the Belfast Agreement).
 The agreement consists of two related documents, both agreed on Good Friday, 10 April 1998 in Belfast: in the Republic, voters voted on the nineteenth amendment to the Irish Constitution. This amendment allowed the State to comply with the Belfast Agreement and provided for the removal of the „territorial claim“ contained in Articles 2 and 3. On the same day, a referendum was held on the Treaty of Amsterdam (the eighteenth Amendment of the Irish Constitution). The referendum in the Republic of Ireland took place on the same day, but instead of expressly seeking approval of the agreement itself, it sought to approve the constitutional amendments required by the agreement and led to an overwhelming „yes“.