While Nzimande said the SACP would not get involved in the ANC succession battle, he boasted about the party's "great relationship" with the current ANC leadership.

"There has been a huge difference," said Nzimande, adding that cooperation between the alliance partners was "better than before".

Zuma, who became party president when Thabo Mbeki was ousted from the party's top six in Polokwane in 2007, will have to fight to hold onto the position in December, when the ANC holds its elective conference in Mangaung.

His re-election as party president is uncertain, with calls from the ANC Youth League for him to be replaced by deputy president Kgalema Motlanthe.

It recently emerged that Human Settlements Minister Tokyo Sexwale is also vying for the ANC top spot.

Said Nzimande: "The question of ANC leadership is a matter for the ANC."

The ANC itself has called for the succession debate to be opened only in October.

Nzimande, speaking at the release of the SACP's 13th national congress discussion document, refused to comment on Zuma's failure to deal with the controversy around spy boss Lieutenant-General Richard Mdluli.

He said the matter was between the South African Police Service and its employee.

"We can't be sensational and seek headlines by talking on it."