The Sinn Féin president, Mr Gerry Adams, has said that the defence of the peace process must involve opposition to violence "by anyone".
He also accused the Taoiseach of "crossing the line" in his attitude to republicans.
He said "malign elements in the British system" were laughing at the "outbreak of civil war within Irish nationalism".
Mr Adams's repudiation of violence from any quarter comes ahead of today's publication of the report of the Independent Monitoring Commission, which is likely to propose sanctions against Sinn Féin over the £26.5 million Northern Bank robbery.
The report is due to be published at about noon. It is expected to recommend financial penalties against Sinn Féin.
Mr Adams, speaking in Belfast yesterday, said it was the success of Sinn Féin which had "unleashed a torrent of abuse".
"It is almost like the days before the peace process, when the Irish and British establishments and unionist parties ganged up, trying to outdo each other in anti-Sinn Féin hysteria, aided at times by compliant sections of the media."
He said that the Government was at the forefront in the attack on Sinn Féin.
"The Taoiseach, in particular, has crossed the line on a number of important issues and is in the business of imposing or supporting the imposition of preconditions on the rights of Irish citizens."
He said that Sinn Féin would continue to make political advances.
"What is that work? To continue the process of change by defending the peace process, by opposing any return to violence by anyone, including British government agencies, by campaigning for the equality and other elements of the Good Friday agreement, and by upholding the rights of all citizens, including those who vote for our party."
SDLP Assembly member Mr Alex Attwood said that Mr Adams was engaging in "breathtaking self-righteousness" in claiming that all that remained of the process was the IRA ceasefire. "Sinn Féin says there is a civil war within Irish nationalism. There is not. Irish nationalism, the people and the political parties are united, and it is Sinn Féin and the IRA who are in conflict with their views. This is not civil war, this is a refusal to bend on democratic values," he added.