The African National Congress (ANC) would comply with the Constitutional Court findings and go back and contest the Tlokwe by-elections, secretary general Gwede Mantashe said on Monday.
"One of the things we [are] known for, except the Al-Bashir case, is to comply with court decisions," he told reporters in Johannesburg, while chuckling.
"This is no different. If the court says there must be elections, we will go to the by-elections, campaign and win again."
Earlier on Monday, the Constitutional Court set aside the results of the controversial by-elections in several Tlokwe wards, finding they were not free and fair.
It set aside the by-elections conducted on September 12 2013 in ward 18, and on December 10 2013 in wards one, four, 11, 12, 13 and 20.
The court decided the by-elections should be rerun.
The applicants were eight independent candidates who had contested the by-elections. The ANC won all but one of the contested wards.