The two groups said in a joint statement on Friday that they plan to raise these in response to the publication of the green paper, a discussion document released for public comment.

What was required were measures to ensure transparency of tariff structures, reasonableness of prices, significant improvements in the quality of public health and a proposed office of health standards compliance.

"With this in mind, we commit ourselves to defending the [health] minister's right, essentially a constitutional obligation, to take all reasonable evidence-based measures necessary to restructure the health system," said Section27 and TAC, which lobby for comprehensive care for people with HIV-Aids.

According to some details of the NHI released on Thursday, everybody over a yet-to-be-determined income threshold would be legally required to contribute.

Money would come from four sources: the tax everybody contributes; mandatory contributions from individuals and employers; co-payments and user charges from individuals; and certain public-private partnerships.

The government did not intend abolishing private medical schemes.

A conditional grant would be allocated in the 2012 budget to fund NHI pilot projects, which would start that year at 10 selected sites. These would be selected based on the outcomes of a planned audit.

Details TAC and Section27 believed the green paper did not cover included information on the source of funds, the future role of medical scheme administrators, and what the benefit packages would be.

They also wanted to know where refugees, asylum seekers and non-citizens stood, as well as more information on the nature and governance structure of the NHI fund, which they believed did not have adequate structural and operational autonomy.

Business Unity SA supported the NHI's "social imperative", but warned the cost, design and institutional changes would require vigorous debate.

"If additional funds are to be allocated to public health, it is imperative that they be effectively used."

The concepts contained in the green paper would affect household budgets, public finance and the labour market, so phasing in and consultation with the National Economic Development Labour Council was also called for.

The People's Health Movement, an NGO that promotes "health for all", and social justice movement the Alternative Information Development Centre stressed the importance of strengthening district health facilities.

"In line with the primary healthcare approach, this will require both active community participation and a collaborative intersectoral approach by a range of government departments and will require significant policy changes."

They would study the green paper and decide whether it offered a comprehensive health service where nobody had to pay at the point of delivery.