The Minister for Foreign Affairs, Mr Dermot Ahern, and the Northern Secretary, Mr Paul Murphy, said today the two governments were 100 per cent sure the IRA was behind the £26.5 million sterling heist at the Northern Bank last month.
Speaking after a working lunch in Dublin today, the two men said the Provisionals' involvement in the raid was a massive setback for the peace process. Both also said the timetable for resolving the outstanding issues blocking the restoration of devolution in the North had been seriously affected.
"It is not business as usual. This turn of events has caused extreme difficulties," Mr Ahern told reporters.
"Both governments remain firmly committed to achieving inclusive political arrangement in Northern Ireland," he said. "But we are very unlikely to achieve that outcome in the very near future."
Mr Murphy said: "The world has changed in terms of how we deal with the Good Friday Agreeement.
"The impact of this event on the mutual confidence, trust and faith has been damaged very seriously."
When both men were asked whether they were "100 per cent convinced" the IRA were behind the robbery, both simply replied: "Yes".
However, talks between the Government and all parties in the North, including Sinn Féin, will go ahead as scheduled over the next week. Talks at the start of February involving the Taoiseach and the British prime minister will also take place.
Mr Murphy later met with the Minister for Justice, Mr McDowell, where he reiterated that "both governments are at one about who carreid out this act".
The meetings follow PSNI Chief Constable Hugh Orde's claim that the IRA carried out the heist. Mr McDowell said after his meeting with the Secretary of State that Mr Orde was not "trying to please someone's political agenda" when he made the statement.
He refused to reveal any intelligence the Garda may have on the robbery but indicated they had not told him anything that contradicted Mr Orde's assertion and promised "the Garda will co-operate completely with the efforts to track down the perpetrators".
Sinn Féin's chief negotiator, Mr Martin McGuinness, said yesterday there was still no evidence that the IRA had carried out the robbery and he warned the SDLP against adopting the idea of a voluntary coalition as an alternative to the power-sharing executive.
The possibility of such an arrangement was not ruled out after today's meetings despite the DUP in recent days pressing for devolution without Sinn Féin involvement.
The reaction from Mr Murphy and Mr Ahern was cool and Mr McDowell said: "The governments are committed to the Good Friday Agreeement, there is no other show in town, there is no other political project", which effectively precludes the possibility of proceeding without Sinn Féin as they are supported by the majority of nationalists in the North.
Earlier today the DUP leader, Dr Ian Paisley, said: "The criminal structures of IRA/Sinn Féin must be totally dismantled and proof of this must be demonstrated, without question, over a substantial period of time and accepted to be so by the law abiding population of Ulster.
"Until action on these matters is taken, the British Government must declare categorically that IRA/Sinn Féin have put themselves outside the negotiations and can have no place whatsoever in the executive government of Northern Ireland."