The African National Congress (ANC) has lost more than half of its electoral support in Johannesburg over the past decade, according to projections by the Council for Scientific and Industrial Research (CSIR).

In the 2016 local government elections, the ANC secured 45% of the vote in Johannesburg, making it the city's largest party.

The CSIR now projects the party will secure just 20% in 2026, a decline of 25 percentage points over the decade.

The Democratic Alliance (DA), meanwhile, has been comparatively stable. It secured 38% in 2016 and is projected to secure 34% in 2026, a decline of four percentage points.

The DA therefore holds a projected 14 percentage point lead over the ANC, despite also recording a modest decline in support since 2016.

One of the most significant developments has been the emergence of ActionSA, which did not exist in 2016 and is now projected to secure 17% of Johannesburg's vote.

The MKP is projected to secure 5%, while the Economic Freedom Fighters (EFF) are projected to decline from 11% in 2016 to 7%.

The figures, set out in the chart below, illustrate the extent to which Johannesburg's political landscape has fragmented.

The ANC's decline has not translated into an equivalent increase in DA support. Instead, newer parties have established themselves as substantial players.

With neither major party approaching an outright majority, the projections indicate that coalition negotiations will remain central to determining who governs South Africa's economic capital.