Stepping inside, I see that reception consists of a desk manned, according to their name-plaques, by Messrs Mohammed El Alaka and Fadhil Sharad. This is the HQ of the world's biggest oil barons - Saudi Arabia, Iran, Iraq, Venezuela, United Arab Emirates, Nigeria, Kuwait, Libya, Algeria, Indonesia and Qatar - but so far there's nothing slick about Opec.

`Salam aleikum [Peace be with you]. Azayek? [How are you?]' I venture. 'Waleikum salam [And peace be on you],' Mohammed replies, pulling on his cigarette. His colleague continues to eat a sandwich.

Mohammed comes from Egypt. It seems a long way to go to recruit a receptionist, but it allows me to compare the weather in Cairo with that of Vienna. Outside, the Danube is blurred beneath thick falling snow.

After a few more pleasantries, I am whisked upstairs to meet Dr Ali Rodriguez-Araque, Opec's new secretarygeneral. Like the rest of the Opec building, his office has a forlorn, 1960s sort of air. Someone has filled it with enough greenery to recreate the jungle, perhaps in the hope of making him feel at home.

Dr Rodriguez, a former Venezuelan oil minister, is a small man, elegantly dressed in a grey suit and blue silk tie. This is the most powerful figure in the cartel, the oil baron's oil baron. He co-ordinates the bickering oil ministers and ensures that Opec speaks with a single voice. In the imagination of Opec's critics, I suppose, he's the evil genius, the Blofeld de nos fours who can send the price of four-star rocketing with a twitch upon the tap. He's the South American frontman for Arab sheikhs who bathe in milk, treat London and Paris as glorified bordellos, and fritter millions on blackjack. As the American economic com

mentator Irwin Stelzer wrote recently, on the subject of oil-price rises and Arab ingratitude: `Powell and Cheney took the decision to risk American lives to prevent Kuwait from becoming a province of Iraq, while some members of the Kuwaiti ruling class fled to the Dorchester hotel and disported themselves in Harrods and in London's casinos.' Rodriguez is not impressed by this line of criticism. The comment has a `flavour of blackmail', he says in heavily accented English.

Rodriguez has started with a bang. Less than two weeks after becoming Opec supremo at the beginning of January, he announced that the organisation's 10+1 members (under UN sanctions, Iraq is not allowed to participate in Opec decision-making) would cut oil production by 1.5 million barrels a day. With the US economy apparently teetering on the brink of recession, this was not a move destined to win Dr Rodriguez Western acclaim. Worse, he warned that there might be more of the same when Opec meets again next month.

`We thought it was a bit premature,' says Leo Drollas, chief economist and deputy director of the London-based Centre for Global Energy Studies, which describes itself as an independent thinktank. `The decision is not looking good and it's playing a role in bringing on a recession in the USA, increasing costs and lowering profitability. Another cut in production would be over the top.'

Basil Papachristidis, who chairs an oil transportation business, argues that Opec's latest move may be counterproductive. `What's pertinent is whether we agree with the cutbacks Opec has once again decided to impose and whether they are justified. We don't happen to think so. We think cutbacks may not be appropriate now, for the interests of both consuming and producing countries. We don't think the world is awash with oil, and, if Opec pushes prices up too aggressively, it'll simply backfire.' Sharp price rises, according to this analysis, merely encourage both non-Opec oil exploration and the use of other energy sources.

Were Rodriguez to drive his Mercedes 500 on to a British petrol-station forecourt, and announce his identity to those filling their tanks, the chances are that he would not be mobbed by admirers. What does all this talk of `bringing stability to the market' mean? If Opec has brought stability, then why has the price of oil leapt from $12 a barrel in 1998 to more than $25 today? Call that stability, Rodriguez?

`The main point for Opec this year, and in the near future, is to work to guarantee the stabilisation of the market,' he replies steadfastly. `But it isn't enough for Opec to maintain stability. There are many other factors which have influences. As you know, there is the issue of tax within the OECD, and mainly European countries. Then there are problems with transportation, problems with market futures and refining in the USA, and other external economic problems.'

In other words, says Rodriguez, Western pain is nothing - or nothing much - to do with him. Opec's website offers a neat explanation of `Why You Pay So Much for Gasoline and Other Oil Products'. That, and the recent Opec publication entitled Who Gets What from Imported Oil, should make embarrassing reading for our lightfingered Chancellor, Gordon Brown, and his counterparts in consuming countries.

They show, for instance, that taxes represent 68 per cent of the price of a barrel of oil in the European Union. Oil exporters receive only 16 per cent of the final price, with the remaining 16 per cent taken by refiners and marketers. In fact, far from being a low-tax, free-market paragon, the UK is the world's worst culprit, bar none, for pocketing petropounds. In 1995, the price of UK crude was $17.3 a barrel, rising to $21.1 in 1996, then slumping to $12.6 in 1998 before climbing back to $17.6 in 1999. During the same period, composite barrel prices, instead of reflecting this fluctuating trend, rose constantly, from $109.1 a barrel in 1995 to $141.5 in 1999. The statistics are dry, but it's a point worth making. The reason for the inexorable price rises? Step forward the Treasury, whose plunder from every refined-oil barrel shot up from $64.6 in 1995 to a whopping - some would say scandalous - $96.1 in 1999.

Industry experts confirm this analysis. Most of the Opec countries have not been blessed with the temperate climate of Europe or America. They have deserts and rock and blazing sun. But they also have reserves of this one natural resource, and they naturally desire to profit from them. Why should their poor people be prevented from enjoying the prosperity that oil brings simply because Gordon wants to divert money into the British NHS, for example?

'I think it's harsh to blame Opec and equally harsh to blame the oil companies,' argues Steve Turner, oil analyst at Commerzbank Securities in London. `It's a source of great friction between consuming countries and Opec that Gordon Brown gets more out of a barrel of oil than the Saudis or Opec.' (Not only that, but 'Fingers' Brown's oil taxes are non-hypothecated: that is to say, they are only partly directed towards things you might expect, like roads. According to the Centre for Global Energy Studies, the Treasury trousered L35 billion from fuel duty and vehicle tax in 1998-99, yet the Blair government condescended to spend a trifling L5 billion on road maintenance and improvements that year.)