Spain and Poland yesterday spoiled the party for the Italian Prime Minister, Silvio Berlusconi, forcing him to admit that he may be unable to get agreement on a constitution for the European Union by his target date of December.
As Mr Berlusconi launched talks among 25 governments with extravagant ceremony in Rome, the Spanish and Polish leaders vowed to oppose a change to voting rights which would, they say, harm their interests.
Both countries struck a discordant note during a day of high-flown rhetoric at Rome's Palazzo dei Congressi, adorned for the occasion with fake marble columns, in a district of the Italian capital conceived by the former Italian dictator, Benito Mussolini.
Jose Maria Aznar, the Spanish Prime Minister, was characteristically blunt, shaking off claims that Spain and Poland were isolated and arguing that "if you want to negotiate it is better to be feared".
Britain, by contrast, went out of its way to be accommodating to the Italians, who hold the presidency of the EU, as Tony Blair prepared for a one-to-one dinner with Mr Berlusconi last night.
With the EU due to expand from 15 to 25 members next May, the constitution is designed to make Europe's creaking structure more efficient and effective.
Mr Berlusconi wants to clinch a deal on a constitution by the end of the year, and has a draft text on the table from the former French President, Valéry Giscard d'Estaing.
But any nation can veto an agreement, including, for the first time, the 10 countries that will join the EU next year.
Problems confronting Mr Berlusconi include a rebellion by the EU's small countries, which are insisting on the right of each nation to send a full voting commissioner to Brussels.
The UK still has worries over plans for defence and foreign policy, and is resisting plans to scrap the national veto in limited areas of tax and social security policy, the EU budget and some areas of criminal procedural law.
But the biggest problem comes from Spain and Poland, which oppose M. Giscard's scheme whereby decisions taken by majority votes would need the backing of half of the EU member states, providing they represent three-fifths of the EU's population.
Instead, Warsaw and Madrid want to go back to a complex weighted voting system, agreed at a summit in Nice in 2000, which favours nations of their size. Poland's Prime Minister, Leszek Miller, warned that his tough stance is "unequivocally supported by the Polish parliament".
At yesterday's gathering several countries demanded the inclusion of a controversial reference to Christian heritage in the preamble of the constitution, something opposed by France.
However there was some consensus yesterday when the governments agreed to kill a proposal to unite all EU ministerial decision making in a "legislative council". That plan was opposed by the UK on the basis that it resembled an EU government.
Mr Berlusconi acknowledged that the talks "could founder" on Spanish and Polish objections.