Of all the issues under discussion in Doha, none is so urgent as access to medicines for poorer countries. With 36 million people infected with HIV, 25 million of whom are in Africa, the high cost of medicines is condemning millions of people to an unnecessarily early death.

Some countries, such as Brazil and India, have been producing cheap, generic versions of the expensive drugs that can allow people with HIV to live a relatively normal life. But pharmaceutical companies complain that, by breaching their patent rights, such countries are in conflict with WTO rules.

The WTO's Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) covers everything from copyright and trademarks to trade secrets and patent rights. Article 8 of the agreement states that WTO members may "adopt measures necessary to protect public health and nutrition provided that such measures are consistent with the provisions of this Agreement".

The interpretation of this article has been at the heart of this week's debate in Doha.

The US, Switzerland and Japan came to the talks calling for a restrictive interpretation that protects the rights of pharmaceutical companies and limits the grounds on which developing countries can issue "compulsory licences" to produce drugs cheaply.

Developing countries wanted a liberal interpretation that would exempt any action necessary to protect public health from WTO rules. They also wanted poor countries that are unable to produce drugs themselves to be allowed to import cheap versions from countries such as Brazil and India.

The European Union presented itself as an honest broker between the two sides and EU officials worked hard to produce a compromise declaration.

By last night, all sides were preparing to accept a statement that the TRIPS agreement "shall be interpreted and implemented in a manner supportive of WTO members' rights to protect public health and in particular to ensure access to medicines for all". The only uncertainty surrounds the use of the word "shall" in that sentence. India has threatened to reject the deal if "shall" is replaced by the weaker "can and should", which many other members prefer.

The declaration, if it is adopted, represents an important success for a coalition of 71 developing countries and a significant climb-down for the US. The new interpretation of the rules mean that poor countries may produce cheap versions of drugs for such conditions as malaria and tuberculosis as well as HIV.

But many activists for better access to healthcare were disappointed at the fact that the declaration instructs the Council for TRIPS, a WTO subcommittee, to consider whether countries should be allowed to export cheap versions of drugs.

They fear that, away from the media spotlight that surrounds this week's meeting in Doha, officials from developed countries will adopt a tough line on the issue.

Mr Andrew Kailembo, general secretary of the African Trade Union Congress, said it was impossible to overstate the importance of access to medicines for African countries.

"If you have affordable, cheap drugs, the people can survive. This does not just affect the people involved, it affects the development of the country," he said.