The split in South Africa's ruling African National Congress turned ugly yesterday at a rally called by the breakaway faction leader Mosiuoa Lekota in this giant squatter camp 30 miles (50km) south of Johannesburg.

ANC loyalists chanted “Kill Lekota!” as they confronted his secessionist supporters, who tore apart ANC flags, an act regarded as treasonous by party diehards. Police units - supported by armoured vehicles and with helicopters overhead - lined up between the two sides to prevent violence.

Yesterday's rally was a first testing of the waters for Mr Lekota, a former Defence Minister nicknamed “Terror” for his attacking prowess on the football field. It comes before the planned launch of a new opposition party on November 2. Mr Lekota resigned from the ANC after the ousting of Thabo Mbeki, the former President, last month and announced that he would form a “new ANC” to contest elections due in May.

Sam Mbhazima Shilowa, an ANC heavyweight, joined his faction, resigning both from the main party and as premier of South Africa's most economically powerful province, Gauteng, which contains Johannesburg and Pretoria. His resignation underlined the depth of the divisions in the movement for which Nelson Mandela spent 27 years in prison and follows a three-year power struggle between Mr Mbeki and his former deputy, the current ANC leader, Jacob Zuma.

The split in the party that overthrew apartheid is the most serious in its 96-year history. Analysts point out that the new party could not beat the ANC at the next election but might reduce its majority in Parliament dramatically and prevent it from winning control in as many as three of the nine provinces. The Nobel peace laureate Archbishop Desmond Tutu, a lifelong ANC supporter and icon of the freedom struggle, has said that he will not vote for Mr Zuma's ANC in May.

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