Aids activists from G8 countries have formed a Make Aids History coalition to make the most of their shared aims and a government commitment to fight the disease.
Jess Worth, HIV and Aids campaigns and research officer at coalition member ActionAid, said the move made sense because the groups were already in close contact and sharing information.
"This year's G8 summit is seen as an unprecedented opportunity to make a breakthrough because of the enthusiasm of the UK's Government," he said.
The coalition, which also includes Oxfam, VSO and the Stop Aids Campaign, is calling for G8 nations to act on their promise to pay into the global fund set up in 2001 to fight HIV, Aids, malaria and tuberculosis.
"It has been seriously under-funded," said Worth.
The UN estimates that a worst-case scenario would see 90 million new Aids infections in Africa by 2025.