The African National Congress (ANC) is growing of weary of its alliance partner the Congress of South African Trade Unions (Cosatu), party spokesperson Jackson Mthembu said on Friday.

Mthembu conceded that Cosatu was causing instability within its alliance with the ANC and the South African Communist Party.

"Taking pot-shots at the ANC and its government show signs by Cosatu of veering toward oppositional politics and not sticking to alliance politics and traditions," Mthembu said.

The ANC's frustration with Cosatu boiled over after the union's general secretary on Thursday accused a faction of ANC leadership of wanting to oust ANC secretary-general Gwede Mantashe before his term ended.

Mthembu said that Cosatu had "rubbished and undermined" the contents of President Jacob Zuma's State of the Nation address, Finance Minister Pravin Gordhan's Budget and ANC policies.

He questioned Cosatu's motivation for this, accusing it of not raising these concerns with the ANC, but rather in the media.

However, Cosatu secretary-general Zwelinzima Vavi complained on Thursday that progress made during alliance discussions did not filter into the ANC government's policy.

Mthembu said that the ANC was disappointed at Cosatu's conduct and would immediately call for a bilateral meeting with its partner.

He cautioned that Cosatu's behaviour was weakening the alliance, but added that it was not in danger of coming to an end.

Rather, it was an attempt to correct how the partners related to one another.

"Communicating among each other through the media is not how the alliance has operated over many years. Taking pot-shots at the ANC through cheap news headlines will not serve to build the alliance but to weaken it."