The Global Health Fund was set up to tackle Aids and other serious diseases.

BBC Health Correspondent Karen Allen explains how it works.

What is the Global Fund ?

It was the brain child the G8 group of industrialised countries when they met two years ago and was ratified by Kofi Annan last year at the UN Special Session he called on Aids.

It was established to provide funding for countries worse affected by HIV/Aids, Malaria and TB and aims to raise $10billion every year.

What will the money directed at Aids be used for?

It is intended for Aids prevention projects, but there are instances where they will grant funding for treatment as well.

That is important because 96% of people in the world who have the Aids virus cannot get hold of expensive drugs.

Campaigners say that if there is no hope of treatment, people will not come forward for HIV tests in the first place.

Why is it controversial ?

The concept of the fund has been broadly welcomed but many doubt it will be able to secure the resources live up to expectations.

So far only $2 billion has been raised and there is disappointment that richer nations like America have only donated $500 million.

US Health Secretary Tommy Thompson was shouted down when he tried to address the XIV International Aids Conference in Barcelona earlier this week.

Backstage afterwards he angrily told reporters that campaigners would do better venting their anger out on the rest of the global community.

The U.S has contributed 25% of the amount raised so far.

What has the fund achieved to date?

So far, $616 million has been awarded to 58 projects in 38 countries around the world.

These range from youth prevention programmes in the slums of South Africa to tackling the spread through drug abuse in Ukraine.

Those in charge of the fund believe that, thanks to this cash sub-Saharan Africa will see a six fold increase in the numbers of people gaining access to anti-retroviral drugs.

But with only 30,000 getting them now - out of a region where 28m are infected - that is a drop in the ocean.

The fund has also been massively oversubscribed with requests for cash.

Many fear that if it can't get richer nations to dig deeper into their pockets now what hope is there for the future?