For almost 180 years after France abolished slavery, the Code Noir (Black Code) allowing enslaved humans to be treated as property and worked, beaten, sold, raped or killed, remained in place.

On Thursday, the country’s bitterly divided national assembly voted unanimously to repeal it, in a rare show of political unity.

The vote, passed by 254-0, puts an end to a 17th century law, signed by King Louis XIV in 1685, which codified the treatment of enslaved people in France’s colonies.

It is an important step in acknowledging Paris’s role in slavery and will open the way to possible reparations, an idea floated by France’s president, Emmanuel Macron, last week.

The French leader said the code “should never have survived the abolition of slavery” in 1848.

“The silence, even the indifference, that we have maintained for nearly two centuries towards this Code Noir is no longer an oversight. It has become a form of offence,” he added.

Macron added the issue of reparations was one “we must not refuse”, but the country “must not make false promises”.

Emotions were high in the lower house of parliament in the debate on the vote, with many astonished the law still existed.

Steevy Gustave, an MP from the French island of Martinique in the Caribbean whose ancestors were enslaved, was tearful as he told the national assembly: “No vote alone can repair centuries of shattered lives.

“We are not descendants of slaves, we are descendants of human beings born free, then reduced to the worst – reduced to slavery.”

The 60 articles within the code encompassed every aspect of a slave’s life. Article 44 declared a person “movable property”, while other clauses decreed those who fled be mutilated and that the word of an enslaved person counted for nothing.

Max Mathiasin, a French MP from Guadeloupe in the southern Caribbean, who tabled the motion repealing the law said he had bought copies of the original text but had never got around to reading them.

“As the great-great-grandson of people who were enslaved, I had never been able to read it in full. This was made by human beings, against human beings,” he told Associated Press.

He said the vote was “a way of restoring our ancestors, restoring our humanity”. It meant living up to the French Republic’s promise of liberty, equality and fraternity, he added.

France was the third-largest slave trading nation, after Britain and Portugal. It shipped an estimated 1.4 million Africans to sugar plantations in its colonies. The wealth it produced built the cities of Nantes and Bordeaux.

The wealthiest of those plantations were on Saint-Domingue, a French colony on the western third of the Caribbean island of Hispaniola, established in 1687. In 1804, those enslaved in the colony rose up, securing independence in the territory that became Haiti. However, Paris forced the freed slaves to pay reparations to cover their owners’ losses, a debt they were still paying until 1947.

After abolishing slavery, France maintained a number of its colonies. The four oldest – Guadeloupe, Martinique, French Guiana on the north-eastern coast of South America and the island of Réunion in the Indian Ocean – were made French overseas departments in 1946. Their 1.9 million population, most descended from enslaved people, are French citizens and governed from Paris.

Although regarded part of France, they remain some of its poorest territories with unemployment almost double the rate in mainland France, with many households living below the national poverty line.

“In Guadeloupe, the most important positions in the structures of the state are held by whites,” Mathiasin said.

Pierre-Yves Bocquet, the deputy director of France’s Foundation for the Remembrance of Slavery, said the code was at the root of the country’s “colonial exception” installing the idea that the founding motto of the French republic did not apply to certain people under its rule.

“Even today, we accept that people in the overseas territories can have fewer rights than in mainland France,” he said.