With Tony Blair and John Major visiting Belfast yesterday to promote the agreement, the drive is now on for a substantial "yes" vote in the 22 May referendums on the accord.
Sinn Fein's executive committee will ask a special conference, due on Sunday, to drop the decades-old stipulation in its constitution against members taking seats in a "partitionist" Belfast institution.
It is believed the IRA has approved the move in a decision thought to have been taken at an IRA convention in the Irish Republic last month. A two-thirds majority is required at the conference, though with IRA and Sinn Fein leaders in favour, the result is in little doubt.
The historic nature of the move can be seen in the fact that both the Provisional IRA and Provisional Sinn Fein were formed in 1969 by dissidents who left partly because of plans to drop abstentionism.
Meeting on Tuesday, the Sinn Fein executive, gave qualified approval to the Good Friday agreement, deciding to propose changes to the party's constitution and to call for "yes" votes in both referendums. In a statement to be placed before the conference, the executive said that while the Good Friday document did not go as far as it would have liked, it heralded major change, weakened the union and was all-Ireland in character.
Saying a transitional process could provide a pragmatic route to Irish independence it added: "It is another staging post on the road to a peace settlement."
The republican stance drew a guarded public welcome in London and Dublin, although privately both governments will be pleased. The move, while highly sensitive in republican terms, reflects the fact that nationalist approval for the accord is close to unanimous.
A claim by Ulster Unionist leader David Trimble that the IRA intended to shortly de-commission a token amount of weaponry was dismissed by Sinn Fein as "a flight of fancy".
Last night, the Prime Minister and his predecessor answered questions from sixth- formers in Belfast. Mr Blair said: "This is a chance for the people of Northern Ireland to make their own history... please take it." For his part, Mr Major said that while he understood the fears of some loyalists, "I just think they are wrong. I think these fears have been unnecessarily exaggerated ... vote `yes', give hope a chance".
Historic union, page 2Reuse content