A South African court ruled today that the country’s bid to withdraw from the International Criminal Court is invalid and unconstitutional — a rebuke against the government of President Jacob Zuma, NPR reported.

The court said the executive did not have the power to withdraw from the ICC’s treaty, the Rome Statute, without prior parliamentary approval.

The opposition Democratic Alliance party, which filed the suit, said the ruling was a “victory for the rule of law.” It said that “South Africa does not want to be lumped together with pariah states who have no respect for human rights and who do not subscribe to accountability for those guilty of the most heinous human rights violations.”

The court did not rule on whether or not South Africa should withdraw from the treaty. Instead, the court order from the North Gauteng High Court in Pretoria focused on how South Africa initiated its withdrawal from the ICC, NPR reported:

“What is so pressing for the national executive about the withdrawal from the Rome Statute which cannot wait for our legislative processes (and possibly judicial pronouncements) to take their course?” the ruling read. “This unexplained haste, in our view, itself constitutes procedural irrationality.”

South Africa was a founding member of the ICC, which prosecutes perpetrators of war crimes and crimes against humanity.

“South Africa’s justice minister shocked the country last October when he announced it would pull out of the International Criminal Court,” Peter Granitz reported for NPR from Pretoria.

Constitutional activists celebrated the legal victory, but warned that the court ruling does not mean South Africa’s fight is over to leave the International Criminal Court, Voice of America reported.

“South Africa is determined to leave the International criminal Court, and I think they are going to follow the necessary procedures that it takes in order to remove themselves,” said Kaajal Ramjathan-Keogh, executive director the Southern Africa Litigation Center. The advocacy group has argued for South Africa to remain in the ICC.

Those who want to leave the ICC will have to take their case to parliament, which is dominated by the ANC. The ANC has been strongly in favor or leaving, and is expected to fight to withdraw from the court.

Legal experts said the issue will come down to politics.

The opposition will fight back hard, said Stevens Mokgalapa of the Democratic Alliance.

“We will definitely be quoting this judgement as a basis for non-withdrawal from the ICC. And we will continue to challenge, through parliamentary processes, any effort to withdraw from the ICC,” he said.

South Africa announced its intention to withdraw from the ICC after refusing in 2015 to detain indicted war criminal Sudanese President Omar Hassan al-Bashir. Bashir was in South Africa at an African Union summit. The ICC had a warrant for Bashir’s arrest.

Burundi and Gambia also announced in 2016 that they were withdrawing from the ICC. New Gambian President Adama Barrow, who was inaugurated in January, told Newsweek that he would reverse former Gambian President Yahya Jammeh’s decision.

The African Union in January called for mass withdrawal of member countries from the Hague-based International Criminal Court in a non-binding resolution that reveals divisions in the organization, BBC reported.

Nigeria and Senegal oppose an ICC withdrawal.

The ICC insists it is pursuing justice for African victims of war crimes. Only Africans have ever been charged by the court, including the presidents of Sudan and Kenya.

The court’s ruling will force the parliament to open up the decision to the public — a critical part of the debate, said Phephelaphi Dube, director of the Centre for Constitutional Rights.

“Now that that process is before parliament, parliament will be forced to open up the process to the public, so in that sense, then the public can then make their comments,” Dube said.

George Mocheche, a professor of international relations at the University of Nairobi, said withdrawing from the ICC would be an abuse of justice and a sign that the Kenyan government only cares about the accused, not the victims.

Victims’ only hope for justice is to be heard in court, he said, and urged the Kenyan government to support the court and embrace an international justice system, according to a Hivisasa report.

The African court system is biased, Mocheche said.

“It’s wrong for African leaders to insinuate that ICC only targets them,” he said. “I don’t think a court can follow you if you’re doing a right thing. We have to reject the bid to withdraw because the court offers a lifeline to victims.”