We've made history today... The judgment brings hope to potentially tens of thousands of women who have HIV

Mark Heywood Treatment Action Campaign

The case - the first major challenge to the government's policy on Aids medication - was brought by a group of Aids activists to force the government to provide such drugs under the public health care system.

The government was not represented in court and has not yet commented on the verdict

They argue that the drug's safety remains unproven and that there are inadequate resources in place to administer it.

Some 200 babies are born HIV-positive every day in South Africa. A government survey last year showed that 25% of pregnant women were infected with the virus.

Breast-fed

The activists, known as the Treatment Action Campaign, had argued in court that irrational government policies were threatening the lives of mothers and children.

They said the government was acting unconstitutionally by failing to provide enough of the drugs which reduce the transmission of the HIV virus from mothers to children.

Mr Mbeki has controversial views on Aids and HIV

The government argued it was introducing nevirapine in a gradual, responsible way.

It says that even if the drug were available, the virus would be passed on to babies, because their mothers breast-feed them.

Although the German firm which manufactures nevaraprine, Boehringer Ingelheim, has offered to provide it free of charge for five years, the government only distributes the drug in a few research sites, reaching about 10% of HIV-infected women.

Half-hearted

But the government says it is concerned about toxicity and says nevirapine cannot be distributed safely. It also argued that the courts have no right to rule on policy decisions.

Activists believe that with political will, the number of children born with HIV every year could be halved.

They say the government is half-hearted, and believe this attitude has its origins in President Thabo Mbeki's own doubts as to the causes, and the extent, of the disease.

Nearly five million people in South Africa are infected with HIV.

Cheap and easy

Although the main method of transmission is through sexual intercourse, the virus can also be passed from mother to child.

About 30 out of every 100 HIV positive mothers pass the virus to their babies, most commonly during delivery when the baby comes into contact with the mother's blood.

Nevirapine is one type of drug which prevents this form of HIV transmission.

Of those available, it is the cheapest and easiest to use - one dose can be given to the mother at the onset of labour and another dose to the baby up to 72 hours after birth.