By Barnaby Phillips BBC Southern Africa correspondent

There are growing signs of divisions within South Africa's ruling African National Crongress ahead of next month's triennial conference.

Eastern Cape is vital to the ANC

A delegation from the ANC's national executive has travelled this weekend to the Eastern Cape, a traditional stronghold, to try to quell discontent within the party.

The ANC's national executive has annulled the results of provincial party elections in the Eastern Cape, and called for a more open, accountable process.

The Eastern Cape matters to the ANC; former President Nelson Mandela and current President Thabo Mbeki were born there, and of South Africa's nine provinces, it will send the most delegates to the upcoming party conference.

President Mbeki is keen to avoid any open signs of dissent.

But the political chaos in the Cape is indicative of a wider struggle for control within the party.

Mbeki's own position is secure

President Mbeki and his supporters have spoken of the danger posed by so-called "ultra-leftists"; those members of the ANC, and its historic allies the trade union movement, and the Communist Party, who are opposed to the conservative economic policies which South Africa has pursued ever since the end of apartheid in 1994.

These policies have won the ANC international praise, but have alienated many of its traditional, poor supporters, who are badly affected by rising unemployment, and who have not felt the benefits of only modest economic growth.

President Mbeki's own position within the party is secure.

He will almost certainly remain in office until 2009, by which time he would have served the constitutional limit of two terms.

But if the ANC cannot deliver improved living standards to the majority of South Africans, it will find it increasingly difficult to control dissent within its ranks.