The British government, by bringing its security services under control, could facilitate the "redundancy" of the IRA, Prof Monica McWilliams told the Women's Coalition annual conference on Saturday.
The British government should move to reassure everybody of its political commitment to the reform process, she said. "That means, amongst other things, going ahead with the promised new policing legislation and reining in its security services.
"Security and policing must move from a war-footing and philosophy towards more normal democratic approaches as levels of violence reduce. Security and intelligence gathering, whether it's the Garda in Donegal, MI5 or the Special Branch, should no longer read like the plot of a second-rate spy novel. It's dangerous and must be brought under control."
Were this to happen, Sinn Féin should join the Policing Board, which would mean the winding down of the IRA. "Republicans, on the basis of these declarations, should move to convince their constituency that the forces of the state will offer them objective and effective protection. The consequence of that is the redundancy of the IRA," she added.
"Gerry Adams constantly reminds us that the IRA will not bow to pressure or to ultimatums. Well and good, but past action had been taken by the IRA in the interests of breaking the various logjams in the peace process.
"The problem is that the yo-yo approach that has served to avert past crises runs the risk of leaving people both cynical and confused. There is now a general consensus the IRA can make concessions when it has a mind to."
Prof McWilliams said the Irish Government must act to assure unionists of its bona fides. It can "provide reassurance by declaring that it would favour power-sharing, devolved institutions for the current territory of Northern Ireland, irrespective of the outcome of any Border poll".
Prof McWilliams, who, with fellow party MLA Ms Jane Morrice, is the main public face of the Women's Coalition, said the Belfast Agreement should not be renegotiated because it was the "most sophisticated and brilliant mechanism for sorting out a centuries-old intercommunal dispute".
But it was being bedevilled by a reversion to sectarian politics for which unionist and republican politicians must take much of the blame, she told 150 delegates at the conference centre in Cultra on the outskirts of Belfast.
"The Women's Coalition believes that we are witnessing not simply a failure of political leadership but that some politicians are now indulging in actively sectarian political leadership," said Prof McWilliams."Sectarian war has for too long been built on both the violence of the tongue and the violence of the gun."
She added that republicans had a tendency to present the agreement as a stepping stone on the road to a united Ireland, which in essence was a sectarian position.
"More important, republicans say to their constituency 'you can have it all, you can have a reformed and equal Northern Ireland state and meanwhile we will keep in being the most sophisticated and powerful urban guerrilla army of modern times'.
"That is prejudice - ignoring and belittling the interests and feelings of the other side - and a massive exercise of power. To maintain the IRA in being while participating in the institutions of the agreement is sectarianism."
Equally, unionists had a tendency to present the entire progress of the agreement as one of compromise and surrender by the Protestant community. "To try and impose 'British' symbols on the police, to put a sectarian spin on police appointments, are attempts to maintain an identification of the police service with one community. That too is sectarianism." She accused the DUP of on the one hand self-righteously condemning all violence, "while on the other proclaiming that Protestants are under attack and must fight back".
