The longstanding feud between former defence minister Lindiwe Sisulu and Democratic Alliance MP David Maynier is continuing unabated, with a blazing row over the possible purchase of a R2bn luxury jet for President Jacob Zuma.

This came as Ms Sisulu called for the deal to be suspended to allow her successor, Nosiviwe Mapisa-Nqakula, to redefine the department's priorities.

During Ms Sisulu's tenure as defence minister she and Mr Maynier clashed frequently over her refusal to fully answer questions about how, and at what cost, the South African Air Force provided flights for the president and deputy president. This included the plan to procure more luxury jets for their use.

Mr Maynier earned Ms Sisulu's wrath yet again at the weekend when he called on Ms Mapisa-Nqakula to cancel a "dodgy" deal to purchase a new Boeing 777-200 "Long Range" business jet for Mr Zuma. He also threatened to refer the matter to Public Protector Thuli Madonsela for investigation.

Despite no longer being at the defence portfolio Ms Sisulu responded furiously, challenging Mr Maynier to "stop making idle threats" and to go ahead and report the matter to Ms Madonsela. She said she was familiar with Mr Maynier's empty bluster and charged that all his previous complaints to the public protector had been without substance.

"In all our actions we always ensure that we receive the right advice before we act, in this matter we received advice from Treasury, the accountant-general and a number of other institutions. We are absolutely convinced that the procurement process we followed is the correct one," she said.

Mr Maynier had accused Ms Sisulu of negotiating a backdoor deal to buy the aircraft before she was "fired" from her post.

"The former minister turned the defence department into a state within a state and refused to disclose any information on capital acquisition projects including the acquisition of 'VIP aircraft' for the South African Air Force. However, the chickens are now coming home to roost as the rot, which set in under the former minister, is being exposed.

"We now know: the defence department is in the process of acquiring a Boeing 777-200 LR business jet for President Zuma as well as a Bombardier Global Express 6000 for Deputy President Kgalema Motlanthe; the acquisition was proceeding after the executive approved the purchase of four new 'VIP aircraft' for the South African Air Force ."

He charged that the deal was conducted outside normal competitive tender processes as required by Treasury regulations and the Public Finance Management Act and that secretary of defence Sam Gulube had accepted the price quotation following a proposal from Boeing.

"However, it is not clear whether a final definitive purchase agreement was signed with Boeing and whether the acquisition of President Zuma's new Boeing 777-200 LR is a done deal," Mr Maynier said.

Ms Sisulu said in order to ensure that the new defence minister was able to decide how best to deal with the issue of VVIP transport and define her priorities, Mr Gulube should suspend the process until the necessary direction from the new minister.

"We wanted her to look at the challenge, analyse it and find the best solution without any pressure," she said.