Anti-slavery campaigners are set to win parliamentary seats after Saturday’s run-off vote in Mauritania, where tens of thousands remain in bondage while authorities say they are working on a solution.

The head of the Initiative for the Resurgence of the Abolitionist Movement (IRA), Biram Ould Dah Ould Abeid, has already won a seat during a first round vote on September 1 despite being in jail for more than a month.

A critic of the regime of President Mohamed Ould Abdel Aziz, Abeid is among the descendants of black slaves elected to parliament in the largely desert country dominated by “White Moors” who are of Arab and Berber descent.

Another IRA leader, Coumba Dada Kane, who describes Mauritania as “one of the last slaving countries on our planet”, has also won as has the speaker of the outgoing assembly, Mohamed Ould Boilil, representing the political majority.

In an electorate of about 1.4 million, hundreds of thousands of people are descendants of slaves.

Experts and anti-slavery associations say some are “still bonded to their former masters” despite slow legal and judicial progress since slavery was officially abolished in 1981.

More than three decades later in August 2015, parliament made slavery “a crime against humanity” punishable by prison terms of up to 20 years by law. Yet little has changed in reality, activists say.

Nevertheless, specialised courts set up in 2015 to try slavery cases have come down hard on offenders since the start of this year.

In March, a court in the Atlantic port of Nouadhibou sentenced a father and his son to 20 years in prison for enslaving a family of four. A woman was jailed for 10 years for doing the same to three sisters.

In April, the court in the coastal capital Nouakchott gave three men the maximum sentence of a year behind bars for denigrating others by addressing them like slaves, a first for such a crime.

– ‘Raised like my own daughter’ –

The severe sentences “constitute significant progress” for Boubacar Messaoud, president of SOS Esclaves (SOS Slaves), an NGO that helped the plaintiffs.

“They are indeed proof that slavery still exists and that government denials are meaningless,” Messaoud said.

Born in 1975 to a family of slaves, Mata Mbeyrik told AFP how he escaped in 2004 and reached a military barracks 400 kilometres (250 miles) away, only to face being sent back to his former masters.

“A human rights organisation in Nouakchott appealed to the authorities and it’s thanks to them that I was saved,” he said.

In 2006, local administrative authorities ordered soldiers to accompany Mbeyrik back to the camp of his ex-captors to free his sisters, brothers and other slaves.

Testimony at slavery trials illustrate how Mauritanian society is tangled in bonds that have linked slaves to their masters for generations at both family and tribal levels.

“I don’t have a child, I have raised this girl as my own daughter, without giving her a wage — that’s true — but I pay for her every need,” one woman in the dock, Ar-Rabiaa Mint Hammadi, told a court before it sentenced her to 10 years in jail.

– ‘43,000 people still enslaved’ –

For IRA president Abeid, claims by the wealthy to have looked after slaves and met their needs are “an old excuse by slave-owners to diminish the crime and justify it.”

No official statistics exist for the number of still enslaved. NGOs have estimated that up to 43,000 people remained in bondage in 2016, constituting one percent of the population.

“Slavery still continues to exist, but it has become more rare,” said the president of SOS Esclaves, Boubacar Messaoud, expressing concern at the potential impact of poverty on young Haratin, or Black Moors.

“If it continues to exist, then we have failed in becoming a society genuinely anti-slavery, mobilised against this phenomenon and committed to its eradication.”

Mauritanian anti-slavery activists make poll wins despite hurdles