Defectors from the ANC won 10 local council seats for their breakaway party in municipal by-elections, in a closely watched ballot ahead of next year's general elections.

Voter turnout was only 26 percent for the 41 by-elections, which were the first races contested by the Congress of the People (Cope), formed by disgruntled former leaders of the African National Congress.

The ANC won 11 of the races, mainly in the economic hub of Gauteng and the Free State province.

Cope fared well in the Western Cape, which includes Cape Town, winning more than one third of the seats up for grabs in the province.

The Democratic Alliance, currently the main opposition, said it was shaking off its mantle as a white party after winning nine seats from the ANC in the Western Cape.

"The results confirm that we are gaining voters who have not traditionally supported us, and retaining the support of those who have," said the party's chief executive Ryan Coetzee in a statement.

"We have significantly increased our share of the vote in the wards we contested, gaining support in black, coloured and white communities."

Smaller parties divided up the rest of the local council seats.

While by-elections don't usually attract much attention the run up to the vote has been quite heated and acrimonious due to the ANC split ahead of general elections in 2009.

Some Cope supporters complained of intimidation by the ANC at the polls.