The Treatment Action Campaign (TAC) and the National Department of Health are set to lock horns again - and this time it is over the exclusion of the activist group and its allies from the United Nations General Assembly Special Session on AIDS (UNGASS). The TAC and Aids Law Project (ALP) has been excluded from gaining accreditation to the critical meeting because the South African government had objected to its participation. It is two of only six international organisations who were denied accreditation.