A former Irish EU commissioner has warned that enlargement of the Union will not be easy.
Mr Peter Sutherland said that while it was inevitable, he thought it was going to be a much slower and more difficult process than many recognised, and would really be addressed only after EMU.
"Indeed, it is my personal belief that the prospect of enlargement actually depends to a far greater extent on the success of monetary union than on what will emerge from the current IGC.
"A successful launching of the single currency would give significant added momentum to the process of integration.
"However, that success can only be guaranteed if, firstly, the euro and the European central bank are perceived by the financial markets from the very outset to be as credible as the deutschmark and the Bundesbank and, secondly, if the non participating member states are reassured that the gap between the core and the periphery will not widen further as a result of their exclusion."
Mr Sutherland, chairman and managing director of Goldman Sachs International, was speaking on political union and the agenda of the IGC at a conference organised by the Irish Centre for European Law in Trinity College, Dublin, on Saturday.
It was increasingly evident, he said, that the pace of integration could no longer be set by the slowest and least enthusiastic.
"Significantly, in the preamble of the treaty establishing the European Community, the six founding member states resolved to preserve and strengthen peace by pooling their resources and calling upon the other peoples of Europe who shared their ideal to join their efforts.
"There can be little doubt that if they had waited until the UK and others were ready before founding the European Coal and Steel Community in 1952, and the European Economic Community in 1958, the EU would not be in existence today."
While flexibility had always been an essential characteristic of the European integration process, an a la carte approach could well lead to a haphazard and destructive fragmentation.
"I believe that if there are to be categories within the Union, they should be strictly defined. Thus, to be within an inner core, the participants would have to accept all the elements on the integrationalist agenda."
Mr Sutherland said no members state could convincingly claim that on accession to the EC/EU it was not fully aware of the fact that it was joining an ongoing process of integration.
When the community was first enlarged the supremacy of community law over national law was well established.
