There has always been a tension at the heart of the EU between two principles, the equality of citizens and that of states. Indeed, its success in balancing the interests of large and small states through mechanisms like the Commission and qualified majority voting has been the remarkable feature of the EU as a polity.
But sometimes things get out of kilter. Accessions over the last few years have tilted the balance and the large states are demanding not just a restoration of the status quo but a radical tilt towards a better reflection of their population size in the voting arrangements.
The irony is that in practice it is unlikely to matter very much. On policy issues the Council of Ministers rarely if ever divides on a large-state versus small-state basis and a change in the relative voting weights is unlikely therefore to change the result of votes.
Those divisions only really emerge in the discussions about institutional arrangements - and then they come out with a vengeance.
In Biarritz this weekend the big boys were also venting their frustration at what they saw as small-state small-mindedness in refusing to concede on the principle of one-commissioner-per-state. The possibility of a Commission of 30 in a few years drives Paris insane.
The gloves came off at dinner on Friday night, away from the gaze even of senior officials. Italy, Spain and Germany, led by France, piled in on top of the small state leaders. Look at the sacrifices we are prepared to make, they said. We are willing not only to forgo our second commissioner but to accept an automatic rotation of commissioners which will at times deprive us too of any seat at the Commission. It got hot and heavy. The French Prime Minister, Lionel Jospin, pointedly reminded the 10 smaller nations that they had acquired a much greater voice on the world stage thanks to the EU.
" Where would you be without the Union?" he was reported by one agency as asking the prime ministers of Luxembourg and of Portugal.
The Taoiseach, Mr Ahern, laughed as he recalled the robust response of leaders like Mr Ingvar Carlsson from Sweden and Mr Antonio Gutterres of Portugal. They gave as good as they got. Our concern, they said, is that a reduced Commission would lack authority precisely if countries like yours were not on it, and legitimacy in our countries if we did not have someone present.
Finland's Mr Paavo Lipponen, clearly aggrieved, said on Saturday: "We shall not accept any blackmail.
. . I would like the [French] Presidency to take a broader vision." Austria's Chancellor Wolfgang Schussel said he feared changes in the Commission would be a first step towards forming an inner group of big states along the lines of the United Nations' Security Council, which has five permanent members and 10 rotating ones.
Commission sources were saying that it might well suit the large countries to see a smaller, weaker Commission that they could control from outside.
Indeed if the Presidency wants to reassure small states that it is not its intention it will have to produce a substantial initiative between now and the Nice summit - a package of proposals involving the Commission more intensively in the EU's flexibility structures may be a possibility.
A package of measures to strengthen the president of the Commission is also likely.
It's pretty clear now that the slimmed down Commission is not a prospect for Nice, but what about later? Some small states like the Dutch have begun to acknowledge publicly that once the union reaches 20 or 25 they will have to reconsider their positions. Sources say the Taoiseach has admitted as much privately. But tomorrow is another country.
What is clear from the weekend, however, is that there is the potential at Nice in December for a significant curbing of the use of the veto, a simplification of the EU's flexibility procedures, and some form of reweighting of voting in favour of the larger states.