STORY: South Africa appears to be on course for its most dramatic political shift since the end of apartheid.

That's as partial results from the country's national election indicated the ruling African National Congress could be about to lose the parliamentary majority it has held for three decades.

With results from less than a fifth of polling stations, the ANC's share of the vote from Wednesday's (May 29) election stood at around 42.5%.

The pro-business Democratic Alliance was near 26%, the Marxist Economic Freedom Fighters around 8%.

According to the Council for Scientific and Industrial Research, which was providing projections to state broadcaster SABC, the ANC is projected to have roughly 42% of the vote when the count is over.

That pitches South Africa into uncharted political waters.

The ANC would need to make a deal with one or more political parties to govern.

It has previously won a majority in every vote held since the landmark 1994 election which marked the end of apartheid and the ascent of Nelson Mandela as president.

But since then the ANC's support has declined amid high unemployment and crime, frequent blackouts and corruption.

The ANC has also seen its support eroded by a newly formed party in KwaZulu-Natal province.

There, uMkhonto we Sizwe led by former president Jacob Zuma, was performing strongly with over 42% of the vote versus around 21% for the ANC.

Under South Africa's constitution the newly elected National Assembly will elect the next president.

With the ANC still on course to be the largest party, its leader Cyril Ramaphosa is likely to remain as president.

However a poor showing could make him vulnerable to a leadership challenge from within the party's ranks.