There was no issue at the summit which so exercised the leaders than their respective countries' voting weights in the EU's main institutions, the Council of Ministers and the Parliament.
National pride more than real political advantage was at stake, pitting France against Germany and Spain, Belgium against Holland, and even Malta against Luxembourg, to mention but a few of the clashes.
Small states demanded parity with larger, while the latter wanted clear water between them and inferior neighbours - no way were the Netherlands going to be grouped with Belgium whose population was a full third smaller!
Population criteria were supposed to be the basis of a reweighting that tipped the balance of power significantly towards the larger member states, but history, clout and being in the EU since its earliest days were also factors.
Indeed, when a Maltese journalist complained that his country, with a population equal to that of Luxembourg, had one less vote in the Council of Ministers, President Chirac of France even suggested that per capita GDP might be a criterion, a peculiarly 19th century notion.
The tables run here yesterday under this heading were an early version of the proposed result, and although today's tables reflect only slight differences, their finalisation was the product of five hours bitter wrangling, and on more than one occasion, threats of walkouts.
Although the summit has extended the range of issues on which decision making will be by qualified majority rather than unanimity, EU leaders have agreed new voting weights and procedures that make the challenge of putting together a majority significantly more onerous.
Depending on their size, member states are allocated different voting weights at meetings of the Council of Ministers.
To obtain a qualified majority a proposition must currently get 67 votes, in practice representing over 58 per cent of weighted votes. That will change with full enlargement to 27 states, to 255 votes, or a minimum in practise of 74 per cent of votes, making majorities far more difficult to put together.
A blocking minority, to prevent a decision being taken, will now consist of 91 votes, or just more than three large states.
There will also be two further requirements to establish a majority: that a majority of states back a proposal, and that the combined weighted vote must reflect at least 61 per cent of the EU's population.
The result is in effect a treble key, guaranteeing that otherwise theoretically possible alliances of small states could dominate the EU. In practice, however, small-versus large-state voting is rare.