JOHANNESBURG - The Constitutional Court hands down judgment on Thursday on whether MP's are allowed to vote in secret in Parliament.
The UDM petitioned the court to allow a secret ballot after calling for a vote of no-confidence in President Jacob Zuma.
Several opposition parties and two civil society groups are supporting the court action.
They believe a secret vote will allow ANC MPs to vote without fear of intimidation.
The President argues that the parties are confusing party discipline with intimidation.
The no-confidence vote was postponed in April to allow the court time to decide on the application.