The global effect of the HIV epidemic was commemorated as World Aids Day was marked around the world, with the launch of an appeal to help other nations deal with the epidemic.

The prime minister is to become a co-chairman of the International Aids Trust where he will serve alongside Bill Clinton and Nelson Mandela. "It is my hope that by working together we can help raise awareness, increase political will and mobilise the resources necessary to stem the tide of this epidemic," he said.

Meanwhile international development secretary Hilary Benn has announced that the UK's funding to UNAids would double to £6 million next year.

The government has been warned that Britain is facing a growing sexual health problem, with HIV rates increasing steadily amongst the heterosexual population. There is now estimated to be 50,000 people living in Britain with Aids ? around a third of which have yet to be diagnosed.

Globally the Aids epidemic shows no signs of abating ? with five million people becoming infected with HIV worldwide and three million dying this year alone.