Johannesburg - As South Africans vote in municipal elections that may herald the biggest shift in the political landscape since the end of apartheid, the ANC has the advantage of incumbency and a R1bn campaign budget that dwarfs all of its rivals combined.

The ANC could slip below 60% for the first time since it took power in 1994, to 54%, and lose its majority in the capital, Pretoria, Johannesburg, the economic hub, and the southern city of Port Elizabeth, according to an opinion poll by the research company Ipsos released on Tuesday. With no party expected to pass the 50% mark in all three centers, Africa’s most industrialised country may be headed for a new era of widespread coalition politics.

“If the polls prove accurate, the election will usher in an era of more competitive politics in South Africa,” Daniel Silke, director of Cape Town-based Political Futures Consultancy, said Wednesday by phone. “That will unsettle the ANC and may unleash a period of intense soul-searching in the party over leadership and policy. There is a lot riding on this.”