For some protestors, evidence of a growing income gap between industrialised and developing countries shows that the liberalisation of markets is simply a recasting of colonialism. Similarly, the fact that income differentials have widened in many industrialised countries over the past two decades is seen as evidence that free trade means putting factory employees out of work for the benefit of multinational corporations.

These contentions are the focus of a fierce and still unresolved debate among academics and policymakers.

Supporters of liberalisation contest the allegation. They say that properly measured - taking the purchasing power measure of national income - poor countries have on average been gaining on the rich since 1980, despite the huge swings in commodity prices and two periods of debt crisis. But, as the economist Mattias Lundberg has pointed out, this ignores rising inequality within poor countries.

He says that total global inequality has, in fact, risen, and goes on to argue that openness to trade exacerbates inequality within developing countries by placing the poor at the mercy of movements in international commodity prices.

This debate is far from concluded, and many policymakers in the development field spent much of last year mulling over controversial work produced by World Bank economists David Dollar and Aart Kraay which argued that the poor benefited as much as anyone else from economic growth.

But the inequality debate has lately taken a new turn with an increasing focus on the "digital divide" - the gap between countries rich and poor in information technology.

As the former South African president Nelson Mandela puts it: "Eliminating the distinction between information-rich and information-poor countries is critical to eliminating the other inequalities between north and south."

The fear is that the internet economy puts an increasing premium on knowledge rather than physical capital, and creates "winner-take-all" markets by lowering transactions costs and ensuring that dominant companies in any particular market rapidly gain a monopoly. And in this area, the divisions between rich and poor are stark: as the UK development minister, Clare Short, is fond of pointing out, there are more internet connections in New York than in the whole of Africa.

Japan set the ball rolling at the Group of Eight rich countries' summit in Okinawa last summer by announcing a colossal $15bn aid package for developing countries to boost their information technology levels. This helped ensure that the summit focused on IT, and produced the Dot.force - a high-level working party including business, government and campaign representatives from each of the G8 countries.

A few tentative proposals are beginning to emerge from the committee, including technical support for developing countries and pushing ahead with telecommunications deregulation.

Meanwhile, some developing country governments are already blazing the trail. In Andhra Pradesh, the IT-rich southern state of India, the dynamic chief minister, Chandrababu Naidu, has already put many of his administration's services online and claims he will connect every village in the state to the internet.

This is greeted with scepticism by many, who point out that the state lacks the power infrastructure to make it viable, and in any case will have little effect on a rural population who are still overwhelmingly poor farmers. The local joke in Andhra Pradesh is that the internet will allow the villagers to e-mail Mr Naidu to tell him they are hungry.

Even when a large IT industry such as that in southern India does develop, its lasting benefits to the countries themselves are unclear: software companies in India say the aim of most of their workers is to emigrate to Silicon Valley in the US.

Indeed, the backlash against an obsession with the digital divide began almost immediately. Protestors burned laptops in Okinawa to indicate their feelings that the argument was misplaced, and even Bill Gates, the chairman of Microsoft, said that the very poor needed food, not computers.

Even those active in the field of bringing information technology to poor countries are also cautious. Vernon Ellis, international chairman of the business services firm Accenture and a UK representative on Dot.force, says: "Information technology is not a silver bullet. You can't just spray IT around and hope things will get better."

The digital divide is the new buzzword of development. But most of the world's poor have hardly yet been touched by the industrial revolution, let alone the technological. And with deep arguments remaining about whether the income gap is widening - never mind what to do about it - the reluctance to open markets and free trade among many governments of both rich and poor countries is likely to remain.