DUP leader the Rev Ian Paisley has set the scene for what promises to be a tough-talking encounter with the Taoiseach when they meet in London this morning.
In their first meeting since the Democratic Unionist Party's triumph over the Ulster Unionists in last month's general election, Mr Ahern will attempt to discover the depth of DUP resistance to the early resumption of negotiations on power sharing with Sinn Féin.
Minister for Foreign Affairs Dermot Ahern and Minister for Justice Michael McDowell will accompany the Taoiseach at a 30-minute "stock take" with British Prime Minister Tony Blair at the House of Commons.
The Taoiseach will be urging the DUP to stick to the political terms of last December's failed "comprehensive agreement" in anticipation of the expected statement about the Provisional IRA's future status.
However, Dr Paisley yesterday warned the Irish and British governments against "getting excited" about what he termed IRA "word games". And he declared: "We will never live to see the IRA in government [ in Northern Ireland] again."
Irish and British analysts will interpret this as meaning Dr Paisley is still not ruling out the possible inclusion of Sinn Féin in any new devolved administration, given the right conditions.
However, Dr Paisley defined his conditions in trenchant terms in yesterday's Belfast News Letter. The DUP leader warned the Irish Government that, if the purpose of the London talks was to try to convince the DUP to give the IRA "a fair wind on the back of a statement", they had "another thing coming". And he declared: "We need actions, not lies and hypocritical words. We need them to decommission totally, transparently. We need them to end all forms of criminality. And we need them to disband forever."
Asked how long they thought would be necessary to test any such commitments if given by the republican movement, usually reliable DUP sources told The Irish Times: "A very long time."
This presents a major difficulty for the Taoiseach, who thought to have done well in persuading republicans last autumn to accept a two-month interval between the completion of IRA decommissioning and the resumption of power-sharing at Stormont.
In addition, Dr Paisley fought the election with a commitment to reject the d'Hondt formula guaranteeing Sinn Féin's "automatic" entry into government, as established under the Belfast Agreement.
Since the election the DUP leader has also questioned the need to construct any devolved administration around the co-equal posts of First and Deputy First Minister.
However, the DUP sources last night also suggested that the outstanding question of devolving policing and justice powers to Stormont on its own was equal to everything else on the agenda. The Conservatives, meanwhile, have challenged Northern Ireland Secretary Peter Hain to spell out what he means in demanding that any IRA statement be "credible."
Shadow Secretary of State David Lidington insisted: "It must include the end of the IRA as an effective paramilitary organisation, an end to involvement in criminal activities of any kind, the complete decommissioning of its illegal arsenal of weapons and explosives, and it must signal the willingness of republicans to support the police and criminal justice system."