Johannesburg — AFRICAN National Congress (ANC) leaders who want Jacob Zuma 's presidency brought to an end face a key conundrum: choosing the right moment to oust him.

Many ANC members remain hesitant to support the removal of a sitting president before he has completed even a single term. After all, Zuma led the movement to a convincing election victory less than two years ago. His early removal would also create fears of political instability and generate outrage in KwaZulu-Natal.

Yet Thabo Mbeki 's "recall" in September 2008 makes such an action conceivable. Moreover, three powerful forces are propelling the President's enemies towards early action.

First, Zuma has packed a lot of mistakes into his brief incumbency. Personal scandal, his family's rapid enrichment, and the absence of a wider vision for the country, have made him the weakest ANC president in living memory.

Second, the anti-Mbeki coalition that rallied behind Zuma at Polokwane has fallen apart, and the President is confronted by enemies of all generations, classes and ideologies. An ANC Youth League fuelled by Gauteng money seems set to turn on him. His instinctive social conservatism and haphazard personal ethics have alienated modernising constituencies, and particularly women, across the ANC.

Now the Congress of South African Trade Unions has seen an opportunity to execute a double revolution, using Zuma to displace Mbeki and organised worker power to remove Zuma.

Third, Zuma's enemies may calculate that it is dangerous to wait.

The success of an anti-Zuma coalition depends in part on the willingness of aspirant successors to suspend their personal ambitions. Inveterate plotters such as Tokyo Sexwale and Mathews Phosa will not stay quiet for long, but both men recognise that they are too weak to displace Zuma today. Indeed, all of the contenders for national leadership appear resigned to the temporary return of Deputy President Kgalema Motlanthe to the Presidency.

The strongest motivation for an early recall of Zuma is that by 2012 it might no longer be possible to get rid of him. If they wait two more years, Zuma's enemies will have to secure the support of increasingly unpredictable branch delegates.

Regional barons who trade money and power in their personal fiefdoms might swing behind Zuma - particularly if they feel he offers protection and further opportunities for enrichment.

It is a sad indictment of the ANC's cynical politics that even the death of Nelson Mandela might be used as a pretext to close down political competition.

Many of the president's key allies are entrenching themselves in security and intelligence agencies. In these positions they are establishing what will become a significant capacity to influence the outcome of internal ANC elections.

Even Zuma's vulnerability to further revelations about his private life might soon be curtailed. Some of the supporters of a media tribunal are keen to protect the "right to dignity" of political leaders - and the president is presumably the primary possessor of this alleged entitlement.

Zuma's strongest resource has been the almost unqualified support he has received in KwaZulu-Natal, where business, labour and ANC leaders have thrown their weight behind him. After a prolonged period of dominance by Eastern Cape elites, the ascension of Zuma is sometimes conceived in KwaZulu-Natal as part of a marginalised province's - and people's - deserved rise towards an era of national hegemony.

Strenuous efforts are under way to accelerate the decline of the Inkatha Freedom Party and so to deepen the ANC's stranglehold over the province. If the ANC's old enemy is liquidated or absorbed by 2012, and the destabilisation of Eastern Cape politics continues, a coherent KwaZulu-Natal bloc could dominate the movement's next elective conference. For this reason above all others, Zuma's enemies may decide to show their hand early and act decisively to remove the president.

Butler teaches politics at Wits University.