The delay in the NPA announcing a decision on whether to proceed with or drop charges against ANC president Jacob Zuma is due to "deep divisions" in the authority, Democratic Alliance leader Helen Zille said on Friday.

"Some in the NPA oppose withdrawing the case that they have so painstakingly built, while others believe the case is seriously compromised, or want to protect their jobs by dropping the charges," Zille said in a statement after the NPA said its decision on the matter would be announced on Monday.

"The NPA is also divided over how much material from the secret Zuma submissions should be made public," she said.

Zille's spokesperson Fritz de Klerk said the party leader's comment were based on her personal observations as well as media reports on the matter.

She said it was "essential, in the interests of saving our constitutional democracy" that there was full disclosure of all information regarding the case.

Almost all parties involved were interested in a cover-up, including Zuma, former president Thabo Mbeki and the NPA itself, Zille said.

The DA has threatened to take legal action should the NPA drop its corruption, fraud and racketeering cases against Zuma.