The Western Cape High Court has ruled that Parliament must amend the Promotion of Access to Information Act (PAIA) so that political parties will be compelled to disclose the source of their private funding.
Judge Yasmin Meer ruled on Wednesday that Parliament has 18 months to rectify "inconsistencies" in PAIA, following an application from non-profit organisation, My Vote Counts.
Respondents included President Jacob Zuma, the Minister of Home Affairs, the African National Congress (ANC) and all 12 opposition parties.
Meer said information about private funding is "reasonably required" for the effective exercise of the right to vote and to make political choices by the Constitution.
"It is declared that the Promotion of Access to Information Act, 2 of 2000, is inconsistent with the Constitution and invalid insofar as it does not allow for the recordal and disclosure of private funding information."
The Minister of Justice and Correctional Services and the Democratic Alliance (DA) were ordered to pay the costs of the application.
Parliament is currently conducting its own process to review how political parties are funded, and a draft bill was drafted last week for review.