Last week, Zille announced that retired Constitutional Court justice Catherine O'Regan and former National Prosecuting Authority boss Vusi Pikoli would head the commission.

The commission was expected to start work next month and publicise its findings early next year.

But yesterday Zille's office received a letter from Mthethwa, requesting a meeting about the proposed inquiry.

Mthethwa wrote that he wanted to avert an intergovernmental dispute because they were constitutionally bound to cooperate.

Zille and Mthethwa have clashed numerous times this year, including over the Western Cape government's plan to enact a bill that would allow it to enforce its oversight role over the police more strictly.

The Western Cape government has also sought to bring back specialised police units, and has called for the army to patrol areas that have been plagued by gang violence. Mthethwa opposed these ideas.

His spokesman, Zweli Mnisi, said that, while his boss respected Zille's right to establish the commission of inquiry, his view was that its establishment was premature.

Mthethwa acknowledged the challenges under which police operated in Khayelitsha but believed they continued "to do their best".

"I therefore, request that you postpone the commencement of the work of the appointed commission of inquiry so that we might discuss the matter to enable us to find possible alternative resolutions, if any, to the challenges that you believe exist in Khayelitsha," wrote Mthethwa.

"I am approaching this request with an open mind, [aware] that, through our pending discussions, should I become convinced that this commission of inquiry is necessary, I shall ensure that my department cooperates fully with it," said Mthethwa.

About 6000 ANC Youth League supporters marched through the Cape Town CBD yesterday, demanding that Zille's government give the homeless access to provincial government-owned land, deliver services and halt the proposed closure of 27 schools in the province .

Zille refused to accept their memorandum, saying the youth league had not disavowed its role in service-delivery protests in Cape Town following a call to make the city "ungovernable".

While a heavy police presence marshalled the marchers into the CBD, ANC deputy provincial chairman Abe Bekeer said Zille should come down from her office "to see how disciplined our people are".