Sinn Fein's support for the Republic's democratic institutions will remain "qualified" until it accepts the Irish Army is the only military force allowed to bear arms here, the Fine Gael leader, Mr Michael Noonan, said.
Speaking at the annual Michael Collins commemoration in Beal na Blath in Co Cork, Mr Noonan gave the latest sign that the Republic's major political parties are preparing to make life more difficult for Sinn Fein.
He declared: "There is only one army in this country. It is the Army, the supreme command of which is vested in the President, in accordance with Article 13 of Bunreacht na hEireann. A political party which does not fully subscribe to this principle cannot play a full part in our political life."
Last week he joined a call, supported by Fianna Fail's Mr David Andrews and the deputy leader of the Labour Party, Mr Brendan Howlin, on Sinn Fein to clarify its links with the three men arrested last week in Bogota, Colombia.
He urged the republican movement to "desist from attempting to introduce its own policing".
"We can be justly proud of our policing tradition in this jurisdiction. As a citizen and as a former minister for justice, I take pride in the achievements of An Garda Siochana," he told the annual commemoration.
"I take particular pride in the fact that they enjoy total public support, which is the only basis upon which we can have effective policing. No group of persons, no matter how or why motivated, must be allowed to undermine or supplant the role of An Garda Siochana.
"No Irish government worthy of the name will tolerate any such attempt."
He reminded the republican movement that the Good Friday agreement included a commitment to decommission all paramilitary arms within two years of its signature. "It is a deadline which has long since passed."
He urged the Sinn Fein president, Mr Gerry Adams, to build on the gains already won. "Show the confidence that the other participants in the peace process have already shown," he said. "You have the ability to achieve the rest of your objectives through the political process and not through threats of withdrawing co-operation from the International Decommissioning Body."
During his lifetime, Michael Collins had placed "a heavy emphasis on the maintenance of public order, the security of life, personal liberty and property. Nor it is surprising that he should have stressed the importance of the role of the Army in the functioning of the State.
"The positions on public order taken by Michael Collins over 80 years ago are as relevant today as they were when he articulated them," he said. "If democracy is to function properly and political parties are to play their part in the functioning of that democracy, they must do on a clear and unequivocal commitment to one Army."