Sinn Féin President Mr Gerry Adams has described recent attacks on his party by the Minister for Justice, Mr McDowell as "cynical and unsubstantiated".
During a visit to the Ballymun area of Dublin this evening, Mr Adams described comments made by the Minister in which he compared Sinn Fein to the Nazis as "particularly offensive".
He said Mr McDowell had agreed to meet him about his public attacks on Sinn Féin.
However, the meeting failed to materialise despite several attempts by Sinn Féin to arrange it, he said.
In his speech, Mr Adams claimed the Government was contemplating freezing his party out of the political process in Northern Ireland.
Mr Adams said recent attacks on his party by politicians marked a return to "the old politics of conflict and division".
He said: "Gone are the concepts of inclusivity, of dialogue, of seeking agreement and of working together.
"In my view the Government is actively considering the exclusion of Sinn Fein from the political process in the north as an option.
"It is actively considering going back to the old agenda, the failed policies and attitudes of the past.
"This, like the current negative politics, the negative campaigning, is wrong. It is destructive and it betrays an absence of real political debate on the part of the establishment and it is something that Sinn Fein will not engage in."
As the Taoiseach Mr Ahern prepared to meet Mr Blair in Dublin tomorrow, Mr Adams accused the Government not "fulfilling its role as a co-guarantor of the Agreement".