A host of celebrities including Morgan Freeman, Annie Lennox and Deepak Chopra are backing international health organisation the Global Fund and appealing to the public to support its fight against AIDS, malaria and tuberculosis.

In an open letter on the company's website, the stars are calling for signatures to ensure the lifesaving work, for which America provides a third of the funds, can continue. Minnie Driver, Adam Garcia and Jason Silva have also voiced their support.