Cape Town - The presidency on Thursday reacted angrily to a UDM statement that President Thabo Mbeki and his ministers should appear before parliament's public accounts committee (Scopa) to answer questions on the arms deal.

Mbeki's spokesperson Bheki Khumalo said it would be ridiculous for Scopa to simply summon a head of state, as UDM leader Bantu Holomisa seemed to expect.

The request should be treated "with the contempt it deserves".

"On what basis ex-General Holomisa wishes to demand that Scopa should call the president and ministers before it is as clear as mud. It is politically opportunistic and mischievous, and certainly not a genuine wish for enlightenment, that is behind this demand."

Cabinet ministers had given every assistance to the inquiry into allegations of irregularities surrounding the deal at all stages and would continue to help wherever possible.

"Their efforts have been vindicated by the report and that should be that," he said.

Holomisa said in a statement earlier on Thursday he had written to Scopa chairperson Dr Gavin Woods asking him to invite Mbeki and his ministers to reply to MPs' question directly, "instead of abusing the media to sing their own praises and dodge the issues".

"This will create the opportunity for them to answer the huge questions that remain about the role of cabinet in the arms deal," he said.

A multi-agency investigating team - comprising the Auditor-General, National Directorate of Public Prosecutions and Public Protector - released the report in parliament last week.

The investigation found no "improper or unlawful conduct" by government and no grounds to suggest its contracting position was flawed.

Mbeki and Justice Minister Penuell Maduna have since labelled critics of the report as racists.

The president wrote in the ANC' cyber mouthpiece, ANC Today: "At the base of this lies the racist conviction that Africans, who now govern our country, are naturally prone to corruption, venality and mismanagement."

Holomisa said the executive needed to explain the decision to buy the Hawk trainer aircraft, at twice the cost of the equipment recommended by its own experts.

"It is not satisfactory for the report to simply find that it was the prerogative of Cabinet to overrule expert advice; we need a proper explanation."

Another question related to whether Mbeki and the ministers made any amendments, deletions or "improvements" to the report before it was released to parliament.

He said his party was disturbed by the manner in which cabinet ministers were conducting a media campaign to celebrate their innocence.

"It is simply unacceptable that they repeatedly rebut criticism, not with rational argument but with the race card," Holomisa said.