Unions reacted angrily last night to a claim by the Minister for Finance that a number of them were already acting in breach of the new social partnership agreement.
In a written response to a parliamentary question, Mr McCreevy said a number of current disputes raised questions about the credibility of Sustaining Progress.
His comments were rejected by unions engaged in two high-profile disputes, and described as "totally unhelpful" by the president of SIPTU, Mr Des Geraghty.
Mr McCreevy did not name any trade union and his spokesman said his remarks were not specific to any particular one.
But his criticism is seen as an implicit reference to the long-running strike by public health doctors and threatened industrial action by nurses in SIPTU and staff in CIÉ.
Warning that strikes would have implications for the implementation of Sustaining Progress "in specific cases", the Minister said they raised questions about the credibility of the partnership agreement and the benchmarking process.
Noting that the combined annual cost to the Exchequer of the Sustaining Progress and benchmarking pay rounds was €2 billion, Mr McCreevy said the Government's agreement was dependent on public service modernisation and industrial peace.
"All of the previous agreements contained industrial peace clauses but the provisions in Sustaining Progress were reinforced and underlined to a much greater extent than previously," he said.
"We are now only a few months on from the conclusion of the negotiations and ratification of the agreement and we find ourselves with a number of disputes which, in my view, are in breach of the peace terms of Sustaining Progress - and indeed would have been in breach of the terms of the Programme for Prosperity and Fairness."
Calling for a return to "more orderly arrangements", he added: "Everyone involved knows that industrial relations stability is an essential requirement and must be delivered on. This is what the Government and the public sector unions signed up for."
Mr Geraghty said if the Minister had matters he wished to raise, there were procedures within the agreement providing the "proper forum" to do so.
"Either the Government wants to work through the partnership process or we're going to have these kind of maverick performances by individual ministers."
Mr Geraghty said unions had concerns of their own about other parties not adhering to the agreement. He accused the Minister for Transport, Mr Brennan, of going on a "solo run" in his planned public transport reforms, "when there's supposed to be a partnership approach".
Denying any breach on the part of striking public health doctors, Mr Fintan Hourihan of the Irish Medical Organisation said their claim pre-dated Sustaining Progress and the three previous national agreements.
Mr Blair Horan, general secretary of the Civil and Public Service Union, also denied its members had breached any agreement in their dispute over promotional opportunites in Department of Agriculture local offices.
"If he is referring to our dispute then I simply do not accept what he is saying. Ours is a minor dispute that became a major dispute because of the manager's approach."