Inkatha Freedom Party leader Mangosuthu Buthelezi has vowed to fight corruption in all spheres of government for the sake of party supporters.

"The IFP has a mandate of ensuring the existence of corruption-free leadership in the next several years," he said at a rally at George Goch stadium, Johannesburg.

"I am here to ask for more of your support so that we can work together and end corruption."

Buthelezi said the "high level of corruption" in ANC-controlled municipalities would benefit only those close to the ruling party.

The rally was staged to thank supporters for voting for the IFP in the May 18 municipal elections.

Buthelezi criticised the ANC for what he called "going to bed" with the National Freedom Party, which broke away from the IFP, with the aim of destroying the IFP.

"The ANC was fully behind the establishment of the NFP, financially and otherwise.

"The doomsayers wrote [of] our imminent demise. But the IFP is still alive and kicking," said Buthelezi.

The IFP won Johannesburg's ward 65, which includes the Themba Khoza informal settlement.

The party had two wards in the city before the election, but it lost ward 61 to the ANC.