Campaigning outside a school in a poor black township in the city of East London, Ludimo Sobe and a dozen other yellow and red T-shirted activists of the Congress of the People suddenly start bouncing to the high tempo toyi-toyi rhythm made world famous in the 1980s street mobilisations against apartheid.

“The heart of the bishop is innocent,” they chant, extolling the virtues of Mvume Dandala, the squeaky-clean Methodist churchman who is challenging Jacob Zuma, the controversial leader of the governing African National Congress, in elections later this month.