A united Ireland is "not impossible" and must be put on the British and international political agenda, a Sinn Féin representative said today.
Delivering the opening address at a conference hosted by the party in London to discuss Irish unity, MP Pat Doherty hailed the agreement at Hillsborough reached earlier this month as "part of a process of change".
The deal agreed between the Democratic Unionists and Sinn Féin to save North's power sharing government will see policing and justice powers devolved from Westminster by April 12.
It was unveiled on February 5 by Taoiseach Brian Cowen, British Prime Minister Gordon Brown, First Minister Peter Robinson and Deputy First Minister Martin McGuinness at Hillsborough Castle, Co Down where the parties held nearly two weeks of round-the-clock negotiations.
The agreement met republican demands for the transfer of law and order powers, while detailed timetables also set out a framework to meet unionist calls for a new system to oversee loyal order parades.
Mr Doherty stepped into the speaker's role after Sinn Féin President Gerry Adams, who had been due to open the day of debates, was unable to attend due the illness of his wife who underwent surgery this week after developing cancer.
He said: "Our goal is simply stated: an end to the partition of Ireland; an end to the union with Britain and the construction of a new national democracy; a new republic on the island of Ireland and reconciliation between orange and green."
Mr Doherty labelled Britain's "occupation" of Ireland and its partition as the cause of a "construction of a system of political apartheid".
He said: "The peace process has delivered an end to the war and that is to be welcomed and applauded. However, resolving the many complexities resulting from centuries of occupation and partition was never going to be easy. And for Irish republicans, the cause still persists - the British government's claim of jurisdiction over part of our country.
"It is this denial of the Irish people's right to self determination, freedom and independence which is the core, outstanding issue which must be resolved."
Mr Doherty said his party needed to "address the genuine fears and concerns of unionists in a meaningful way" in order to move forward.
He said: "The Good Friday Agreement is an accommodation, not a settlement. The agreement and the recent progress achieved in negotiations with the DUP at Hillsborough are complementary to this. They are all part of a process of change."
He added: "The Agreement has, for the first time, created a level playing field on which nationalists and republicans and unionists can play out their different positions and let the people decide. It is for the people of Ireland to determine our own future to exercise their right to self-determination."
"The Agreement provides for a constitutional route to Irish unity; that is a significant achievement. Sinn Féin seeks to build on this by working in partnership with others of like mind to build political support for Irish reunification."
He maintained it made economic sense not to have two competing economies.
Calling for the issue of Irish unity to be placed on the political agenda, he said: "Those that understand the rights of the Irish people and the negative role that separate British governments have played in Ireland, have a duty to put Irish unity and independence on that agenda and argue for reunification."
He added: "In recent weeks, many thought the deal between Sinn Féin and the DUP was impossible. Well, apartheid has ended, Mandela was president of a free South Africa, Germany is united, the war is over in Ireland and we did reach an agreement with the DUP at Hillsborough, so nothing is impossible.
"We just have to believe and work hard and the impossible can be achieved. Let me invite all of you as well as people across Britain and all elected bodies to join with us in this historic endeavour moving forward to the reunification of our country."
Labour MP Diane Abbott chaired the initial debate focusing on the prospects for Irish Unity at the conference, which is entitled: Putting Irish Unity on the Agenda.
Introducing Mr Doherty, she said: "One of the things about the Good Friday Agreement...is that as well as creating a power sharing government, it also enshrined the principle of self determination which includes the provision for a constitutional route to a united Ireland. It is that prospect which this conference wants to focus on today."