WHEN, last September, Rome lost out to Athens in its bid to host the 2004 Olympic Games, a cartoon appeared in a local newspaper with the caption: "Why don't we give Athens the millennial Jubilee as well, while the going is good?" If that sounds like typical Roman inability to rise to any occasion, no matter how epochal, then consider a few of the hair- raising facts about the occasion. You have to wonder if the coming celebration will be a spiritual renewal or an impending apocalypse.

The Pope is taking the 2,000th birthday of Christ very seriously, and plans are already far advanced in parishes around the world to send coachloads of the faithful to the fount of the Universal Church. Between 15 million and 30 million visitors, most of them religious pilgrims, are expected to flood into the city in 2000. That's an average of 50,000 a day, and up to 15 times that many for occasions such as Christmas and Easter.

Rome is already a city on the verge of environmental, logistical and infrastructural collapse, where traffic cannot move, hotels are scarce, poorly run and expensive, where the electricity supply seems to be permanently on the brink of overload and frequently cuts out.

How to cope with the influx of pilgrims, who constitute more than twice the usual number of tourists in a city of just under three million inhabitants? When the question first arose four years ago, the mayor of Rome, Francesco Rutelli, was in no doubt. He wanted a new underground train line from the Vatican to the basilica of St John Lateran, via all the tourist spots of central Rome. He wanted key roads widened, including Rome's M25, the notoriously clogged Grande Raccordo Anulare. He wanted to pedestrianise the entire area around the Vatican, and redirect traffic through a new underground tunnel beside the Tiber. "If we don't get this kind of major infrastructure," he told ministers, "how will Rome be able to survive the onslaught?"

The government came up with a staggering 6 trillion lire (more than pounds 2bn) to finance public works in Italy's many pilgrim sites, more than half the money being earmarked for Rome. But then Mr Rutelli's plans began to go horribly wrong. He may have wrung the money out of the treasury, but he had no more than sketches of the works it was supposed to finance.

The first big project to bite the dust was the underground line, vetoed by the public works ministry on the grounds that the government could not pour money into a scheme if it had not been designed yet. One by one the other big projects fell by the wayside for similar reasons, until at last the fate of the whole Millennium lay with one great hope, the road tunnel that would feed into a giant underground car park being built beneath the Janiculum hill.

But the tunnel, too, has just been dropped because the engineering, environmental and archaeological committees involved could not meet their deadlines to approve it. That leaves just the car park. The good news is that it will have room for more than 200 coaches and more than 800 cars. The bad news is it is in the centre of the city and so, in the absence of the other infrastructural projects, will suck all the worst traffic problems into the heart of Rome.

None of these setbacks is a surprise to anyone used to the bureaucratically top-heavy, terminally inefficient nature of public decision-making in the Eternal City. But they are threatening to turn the Papal Jubilee into an urban nightmare that will bring the capital of a major western European economy to a standstill for an entire year.

The Jubilee has made matters worse than usual since the Vatican, as well as the Italian state, is involved - awakening old resentments about relations between the two states, the overlap of spiritual and temporal powers, and the secrecy in which the Vatican shrouds its every move. Nobody knows, for example, how much of its own money the Church is pumping into the enterprise.

"Rome gives the impression of being a city without a government, where all the key interests are controlled by clerics and construction magnates," complained Giovanni Negri, a former parliamentarian who has launched a watchdog campaign to keep an eye on the excesses of the Jubilee.

Mr Rutelli is so alarmed by the impending chaos that he has just sought, and received, plenipotentiary powers from central government so that he can actually make some essential decisions in the 23 remaining months of preparation.

There are signs of discontent in the Vatican, too; the head of the Jubilee committee has just been replaced and dissident clerics are whispering that perhaps it might be better to take the event out of Rome altogether and build a special Jubilee City somewhere more manageable in the countryside.

Officially, the Church takes the line that everything is going according to schedule. "These organisational upsets won't alter the spiritual value of the Jubilee," insisted Angelo Scelzo, editor of the church review being put out for the occasion, entitled Terzo Millennio.

But the average pilgrim could find himself parked out in a hotel in the suburbs of Naples or Florence, woken at 5am for a coach ride into gridlocked traffic, wheeled into St Peter's for no more than half an hour, put back on the coach and then driven at snail's pace to the nearest available airport. That is the scenario that Jubilee organisers, out of sheer desperation, are currently working on.

And what is going to happen to the 6 trillion lire, now that there is little left to spend it on? The government is not going to take it back, nor can the projects be postponed. So the city council is inventing a slew of absurd and costly projects to justify the whole exercise - 40bn lire to teach English to bus drivers and traffic wardens, 6bn just to predict the number of tourists expected to arrive, and another 6bn for something called the "support module for the preparation and management of the Jubilee".

It is hard not to share the pessimism of most Romans, who confidently assume the money will end up lining the pockets of politically-connected construction firms, public-relations companies, phantom state entities and well-connected church groups.

After all, Jubilees were invented by the medieval Popes to bring in money first and foremost, and only then to enhance the spiritual values of the Church's flock. Why should this Jubilee, on the verge of the third millennium, be any different?