Parliament's defence committee is fighting for its right to oversee South Africa's arms exports in the face of calls by cabinet for more secrecy.

Committee chairperson Thandi Modise on Wednesday vigorously defended parliament's right of oversight in weapon sales. But Defence Minister Mosiuoa Lekota equally strongly asserted that politicians could not usurp the function of bureaucrats.

The national assembly's defence committee is considering amendments to the National Conventional Arms Control Bill which has been held up because of Modise's insistence on oversight.

The battle is already two years old, with former MK cadre Modise at the forefront of the committee's bid to play a meaningful oversight role in arms exports.

The committee wants prior oversight and sufficient detail of pending sales.

But Lekota says secrecy provisions in international arms sales, which he insists are the norm, have to be maintained.

If the committee is to vet each application for arms sales, "what is the function of the executive?" he asked.

Many members of the African National Congress and the opposition parties agree on asserting parliament's right to oversight and access to information.

Also at issue is the security classification of sensitive documents concerning arms sales and the degree of accessibility to these documents.

Modise made the telling point that the UN website details arms sales made by South Africa, but she is not able to get this same information in Cape Town.

Lekota said buyers did not mind giving financial details but balked on revealing the quantity or type of weapons bought, for "security reasons".

He warned SA was tied into "past" binational agreements and that SA's arms industry and defence capability could collapse if they were not honoured.

Modise said she was very perturbed by the apparent view of officials of the National Conventional Arms Control Committee (NCACC) - a cabinet committee established in 1995 - who had the attitude that it was sufficient to provide parliament with cursory details of arms sales.

This had set "a big bell clanging in my head", she said.

She questioned how parliament could exercise its oversight role if it got details of arms sales only after the fact. She asked Lekota if it was possible to retrieve arms once they were sold internationally.

Frederick Marais of the NCACC interjected and said that parliament had been provided with details of arms sales as requested.

Modise screwed up her eyes and leaned forward to say to Marais: "If you expect me to congratulate you, then you are wrong." She said she had been waiting for reports for two years and proceeded to lambaste Marais.

The Coalition for Defence Alternatives said it was outraged at the Defence secretariat's efforts to conceal information on arms exports.

It said amendments to the bill proposed by the secretariat would "shroud arms sales in greater secrecy and prevent parliamentarians from exercising meaningful oversight".

With acknowledgements to Andre Koopman, Jeremy Michaels and The Star.