South Africa’s top court said on Tuesday it will consider whether a motion of no confidence against President Jacob Zuma should be taken by secret ballot.

The rand extended its gains to 1 percent against the dollar after the announcement, and opposition parties said there could be a better chance that the motion, when taken, would succeed, if it was held by secret ballot.

The ruling African National Congress party, which has a majority in parliament, has said it will vote against the motion, which is due on April 18. A secret ballot, however, would allow for anonymous dissent.

Zuma, 74, has survived four previous no confidence votes. But opponents, led by the main opposition party Democratic Alliance, believe a recent cabinet reshuffle that led to the dismissal of respected finance minister Pravin Gordhan may have angered enough ANC members to desert Zuma.

“We only need 65 to 70 people from the ANC, and the secret ballot can deliver the votes to remove Zuma,” Bantu Holomisa, head of the smaller United Democratic Movement (UDM), which is also backing the no-confidence vote against Zuma, said.

He earlier posted a court document on his Twitter feed showing the chief justice of the Constitutional Court had given the go-ahead for the parties in the case to give their written submissions by April 21 – days after the no-confidence vote is scheduled to take place.

“The debate on the no-confidence motion against Zuma will have to be postponed, we have written to the Speaker of parliament to pushed it back,” Holomisa told Reuters. “In the event that the Speaker fails to do so, we will seek a court order blocking the debate from going ahead.”

The National Assembly is listed as a respondent in the case.

The ANC Chief Whip’s office has rejected calls for a secret ballot for the no-confidence motion.

(Reporting by James Macharia Editing by Jeremy Gaunt)