Every January, Zurich airport plays host to a peculiar migration when around 150 Gulfstream private jets touch down. The superclass is arriving for the annual World Economic Forum in Davos. If there were only a handful of rich who travelled this way a generation ago, now there are some 1,500 Gulfstreams in service, a symbol of the growth of this new international class of the powerful and rich.

A Gulfstream carries a mere eight passengers in extraordinary opulence; reclining leather armchairs, polished wood panelling and the latest high definition TV. They cost $45m each and $1.25m to service for each 500 hours in the air, so their buyers are, by definition, very rich. Over the past 20 years, Gulfstream sales have followed the booming fortunes of the superclass.

As former US deputy under-secretary of commerce for international trade David Rothkopf writes in his extraordinary new book Superclass, what matters most for these products of globalisation, who declare they have more in common with each other than the mortals 50,000 feet below, is time. They cannot afford, nor wish, to spend valuable hours in airport queues or planes held up by traffic control. The Gulfstream is the indispensable aid to moving around the world effortlessly and that movement, and the global access and influence that comes with it, is one of the characteristics of the members of the superclass .

Rothkopf counts 6,000 of them - CEOs of major corporations, partners in hedge fund and private equity companies, national and religious leaders, a sprinkling of global public intellectuals, military leaders and cultural figures. They control oil, money, intellectual property, technology and the media. Rupert Murdoch is a member, so is Edward Johnson who runs Fidelity Investments, the world's largest mutual fund, as is Lakshmi Mittal who owns the world's largest steel company.

The superclass is overwhelmingly a private affair and most of its members go to extraordinary lengths to keep out of the limelight. Lloyd Blankfein, chief executive of Goldman Sachs, aborted the purchase of a $41m, 10-acre estate on Long Island when the news got out he was the buyer; he wanted his address to be anonymous.

But for all their privacy, they are enormously interconnected. A third went to just 20 universities. The directors of the world's top five companies sit on the boards of another 147 leading companies. It is not just that they can pick up the phone to each other, they have ready access to government, partly because of their power and partly because they know the people personally. Goldman Sachs is the quintessential example. Of Blankfein's four predecessors, two have been secretaries of the US Treasury (Hank Paulson and Bob Rubin), two were head of the US National Economic Council (Rubin and Steve Friedman) and one is the governor of New Jersey (Joe Corzine) Another alumnus, Robert Zoellick, is head of the World Bank.

Gordon Brown has been careful to surround himself with former employees of Morgan Stanley and Goldman Sachs. Jonathan Powell, Tony Blair's chief of staff, now advises Morgan Stanley. And so it goes on.

The financial dimension is key. The superclass can only make the scale of money it does because of its capacity to do what it will with cash - borrow it, leverage it, move it across borders, take over companies with it and shelter it from taxation. Rothkopf says there were 21 financial institutions in 2007 managing assets of at least $1 trillion each and that the top 50 have assets in excess of $48.5 trillion. Their extraordinary freedoms are not natural, or economically efficient, as is now obvious post the credit crunch. They are the consequence of a 20-year-long lobbying campaign to win finance freedoms from national regulation and which are now used against governments to keep them in their place. Brown and Alistair Darling are having urgent discussions, for example, to reshape Britain's corporate tax laws as companies start to move to Ireland to pay less taxation, a classic way the superclass exercises its power (and a classic government response in giving way). The superclass is super-rich - the top 1,000 are billionaires - is super-influential and super-confident.

There has not been a gap between the rich and poor on the current scale ever in history, warns Rothkopf. It is unstable. Sooner or later, there will be popular outrage and a political response. For the moment, though, it seems that a spell has been cast over the political process, at least in Britain. The two frontbenches outdo each other in their anxiety to appease the superclass; Secretary of State for Business, Enterprise and Regulatory Reform John Hutton spoke for both main political parties when he insisted we should praise great wealth.

It fell to Mervyn King, governor of the Bank of England, to point out that City salaries distort the economy by distorting the pattern of reward for talent and to Richard Lambert, director-general of the CBI , to argue that City salaries encourage recklessness.

The difficulty is that to do anything effective requires action at international level. It is not hard to think of a cluster of measures that would limit superclass wealth and sky-high financial market salaries along with constraining the capacity of companies and their superclass directors to avoid tax. You would move at EU level then strike a deal with the US and G8.

But although such measures would be an effective countervailing power, members of the superclass tell us they would undermine UK sovereignty and bring dreaded Brussels regulation into Britain. Euroscepticism is the superclass's best friend, as is undermining all forms of multilateral collaboration.

But if there is not an effective response, sooner or later countries will go it alone. Who isn't spooked by the renaissance of Italian fascism? Challenging times require courageous responses. None is in prospect.