China may not be a member of the World Trade Organisation (WTO) yet, but reminders that it is preparing to join the global trade club after 15 years of laborious negotiations can be seen every day in Beijing.

First there are the hundreds of migrant workers arriving in the city every day seeking jobs, their worldly possessions on their backs. They are among the thousands being laid off every week due to massive restructuring of state enterprises, which is part of China's preparations for WTO entry.

Then there is the growing number of modern high-rise office blocks sprouting up in Beijing, housing multinational companies that are waiting in the wings for the WTO to open up this market of 1.3 billion consumers. But after many false starts and the endless "on-again, off-again" nature of China's negotiations for WTO accession, the prospect of another delay is looming. While substantial progress was made in the late 1990s, important details have still to be worked out.

There is increasing concern about the latest uncertainty over China's entry date. In February, China's Minister of Foreign Trade and Economic Co-operation, Mr Shi Guangsheng, sounded alarm bells when he said China would not be ready to enter the WTO until October or November next.

Three weeks ago, during the annual National People's Congress in Beijing, he delivered the standard line that WTO accession was "not too far off" and a "foregone conclusion".

But, interestingly, he wasn't prepared to give a rough forecast about when Beijing hoped to secure entry. It was impossible for him or any other Chinese official to make that prediction, he said.

Washington is taking a hard line on the issue and the US trade representative, Mr Robert Zoellick, issued a stern warning recently that China would only be admitted to the WTO if it took the steps necessary to conform with bilateral agreements.

The main concern is the fact that no definite date for the next round of negotiations has been set. The incoming WTO chief, Mr Supachai Panitchpakdi, conceded last week that negotiations could drag on into the last quarter of the year.

The biggest sticking point in the negotiations is China's differences with the US over agricultural subsidies. China wants to be classified as a developing country in the area of agriculture so it can qualify for farmer subsidies at the rate of 10 per cent of output. This is crucial for China, which has no intention of turning its back on a farmer population of 470 million.

But the US negotiators, under pressure from the cereal lobby, have firmly rejected this and are insisting on a developed country standard with a farmer subsidy of no more than 5 per cent of output.

China's chief WTO negotiator, Mr Long Yongtu, describes this as "peanuts" compared to the massive subsidies Brussels and Washington pay out to their farmers. But US farmers feel this concession could undermine market-opening benefits that they gained in the 1999 US-China bilateral agriculture agreement.

According to Dr Brendan Smith, the Irish Professor of International Relations at the Beijing-based Chinese Foreign Affairs College, which is affiliated to the Chinese Foreign Ministry, it must be remembered that China still comprises about 80 per cent peasant farmers. It is understandable that the Chinese government will want to maintain subsidies for its farmers much in the same way as the EU and the US have done, he said.

"It will be extremely difficult for the WTO to reach agreement on agriculture given the different interest of WTO states, China included."

However, agriculture is not the only hurdle, and division among Chinese leaders on how to proceed may prove a stumbling block. There are reports of internal arguments over some elements of WTO commitments. For example, there appear to be differences over the drafting of a new telecommunications law necessary to pave the way for membership.

Growing uncertainty in the Chinese leadership over the WTO stems from concerns that sudden exposure to international competition will destabilise politically sensitive areas of the economy, leading to a further increase in unemployment. A more leisurely approach is favoured in some quarters.

Already China has signed a host of agreements in the run-up to WTO accession. It has agreed to huge market-opening changes to its closed economy. It has agreed to slash tariffs and to eliminate import quotas. It has agreed to dismantle export subsidies and has promised to open service industries to foreign companies, including the banking and insurance sectors.

On the positive side, the WTO would contribute to the development of a stronger rule of law and respect for international regulations in mainland China, according to Dr Smith.

"Legal certainty and the rule of law are the key components in attracting further foreign investment and further economic development. Therefore, in the larger cities there will be opportunities for a new middle class in China, an educated elite with marketable skills," he said.

However, he warned that the social implications of the WTO would be dramatic.

Probably no other people in the world have faced such huge upheaval in the past 50 years as the Chinese and WTO membership will ask for more of the Chinese public.

Dr Smith said ailing Chinese businesses, particularly state-owned ones, would be unable to compete with more efficient foreign competitors.

"The government's response to this will be crucial. A situation where the gap continues to grow between a rising middle class and a poorer peasant class could give rise to considerable social unrest," he said.

Dr Smith added there would be a need for changes in the political machinery in China to reflect these economic and social changes. The pressures for political reform will intensify and the Communist Party will have to respond.

While he said he was not necessarily urging China to adopt Western-style democracy, it should reform and develop institutional machinery that best suited the needs of a developing economy.

Some observers say Beijing would ideally like to have talks with the WTO concluded by the summer before it plays host to President Bush at the Asia-Pacific Economic Co-operation forum summit in Shanghai in October. However, this week's diplomatic row over the US spy plane has cast doubt over the summit.

This appears to be an optimistic target, as the wheels of WTO accession grind slowly along.