Congress of the People (Cope) president Terror Lekota and former Public Enterprises Minister Alec Erwin were under an "opportunistic" attack by the Congress of South African Trade Unions (Cosatu), party spokesperson Phillip Dexter said on Saturday.

"...(It) is just plain silly."

He was responding to the trade union federation's call for a full investigation into the A400M military transport plane deal, which would reportedly cost the taxpayer an extra R30-billion.

"The suggestion that these two individuals are responsible for the proposed transaction to purchase the Airbus transport aeroplanes, is just plain silly," Dexter said in a statement.

"Surely even the Cosatu leadership can understand that the
Cabinet assumes collective responsibility for such decisions."

On Friday, Cosatu spokesperson Patrick Craven said it was outraged at what he called "another arms deal scandal".

"The deal, negotiated by the Armscor parastatal in 2005, under (former) Defence Minister Terror Lekota and (former) Public Enterprises Minister Alec Erwin, was for eight A400M military transport aircraft from Airbus at the already exorbitant price of R17-billion," said Craven.

"It has now emerged that no tenders from other companies were sought, and that Armscor has failed to budget for maintenance costs over the life of the aircraft, which have now added R30-billion to the bill."

He said the deal raised suspicions and the new government found itself sabotaged by decisions taken by its predecessor.

"There appears to have been a culture of impunity in government departments in which certain people were untouchable," he said.

On Saturday, Dexter said Cope supported the call for a review "not because there is any evidence of wrongdoing, but because the reported price escalation needs to be explained."

"At this point our country may not be able to afford to purchase these aircraft, even if they are so desperately needed," said Dexter.

He said the inquiry should take into account the potential job losses locally if the contract was cancelled because some of components for the aircraft were manufactured locally.

He asked that South Africans not "jump to premature conclusions".

"While this sort of populist response has become the order of the day in the ruling party and its alliance partners, citizens must make their minds up on the basis of facts," said Dexter.