The BBC's Robin Oakley: "Tony Blair is now urging fellow leaders to launch a new crusade against aids"

The funding is the latest allocation of funds from a five-year �100m HIV support programme announced in January.

The UK's Department for International Development (DFID) says the money will be targeted at a number of initiatives designed to prevent HIV infection spreading further among some of the world's poorest people.

Aids is now the leading cause of death in parts of Africa.

A total of �14m will go to the International Aids Vaccine Initiative (IAVI) as part of a broader HIV-prevention campaign in southern Africa.

The IAVI will use the funds to develop Aids vaccines for developing countries based on local strains of the virus.

The �14m will also support research into developing methods of marketing vaccines in an affordable way.

A further �7.5m will be spent over five years to support a regional response to HIV/Aids in southern Africa. The cash will finance a task force which is being set up to target people at greatest risk from the disease.

Initial efforts will be targeted at Botswana, Lesotho, Namibia and Swaziland.

Training

Around �1.2 million will also be used to train more than 700 volunteers from the Voluntary Service Overseas (VSO) organisation, who will help to raise awareness of the HIV epidemic in southern Africa.

Clare Short, the UK International Development secretary, said: "HIV/Aids is a death sentence for poor and marginaised people. Over 90% of all HIV/Aids cases are now in developing countries - it is overwhelmingly a disease of the global disadvantaged.

"It lays a crippling burden on societies already afflicted by gross inequalities and is sharply reducing life expectancy in many countries.

"HIV/Aids can only be tackled seriously if governments help people to take the virus seriously."

The DFID has made HIV/Aids a priority area of its health strategy and its main aim is to contain the spread of HIV and to minimise the impact of the disease on the health and livelihoods of people in poorer countries.

The UK government has already funded a number of HIV programmes in Africa which it says are making progress.

They include:

• Money for a six-year �35m sexual and reproductive health programme in Malawi. The UK cash covers support for the national HIV/Aids programme, condoms, contaceptives and drugs to treat sexually transmitted diseases
• �1.5m STD/HIV project and �500,000 for HIV testing kits in Nigeria
• More than �2.6m for a reproductive health services programme in southern Africa.