A landmark French bill that would allow for the restitution of 27 objects from France’s national collections to Benin and Senegal before the end of 2021 is set to become law—but only after a last-minute clash.

The bill, which was unanimously approved by the French Senate and deputies from the National Assembly on first reading, stalled after legislators failed to agree on several provisions. But on Thursday, the National Assembly secured the support of the French Prime Minister Jean Castex, overruling the Senate’s objections and approving the bill.

The Senate’s opposition threatened to impede the French president Emmanuel Macron’s efforts to make good on a 2017 promise he made to liberate from French museums African heritage that was looted during the colonial period. The legislation is necessary to pave a legal path around a 16th-century principle that protects objects in the national collection from being deaccessioned.

The two houses of parliament clashed over how restitution requests would be handled. The bill originally proposed by the French Senate included the creation of a National Council that would advise on future claims received by French institutions, but the National Assembly later watered down the provision, adopting a case-by-case approach that would require individual approval from the president.

The latter approach, which would result in a slower process with more oversight from the executive branch, is what was ultimately pushed through despite opposition from senators like Catherine Morin-Desailly, who put forward a motion to oppose the National Assembly’s version of the bill on December 15.

“If we remove objects from French collections as a diplomatic gift at the discretion of the head of state, whoever he is, where are we going?” Morin-Desailly warned during a press conference yesterday. “We must institute a method that is democratic, transparent, and scientific, which allows us to clarify… political decision-making.”

French senators have long been critical of Macron’s case-by-case approach to restitution, finding it inconsistent and unclear. Opponents point to the repatriation of a royal crown to Madagascar last month, which Macron sent back on a long-term loan, bypassing the typical bureaucratic proceedings.

Alexander Herman, the assistant director of the Institute of Art and Law, which is in the process of creating restitution guidelines for UK museums, writes in a blog post that “it is felt that a National Council would provide a forum for experts to discuss and advise on such issues, rather than having final decisions made out of the blue from on high.”

Critics of Macron have pointed out that this approach is typical of the young president, who has a habit of bypassing French administrative norms in order to make good on ambitious promises. Herman notes that, recently, Macron issued a special decree to get around environmental regulations preventing him from using stone quarries in order to keep to his ambitious five-year timeline for rebuilding the Notre-Dame cathedral.

Despite the back-and-forth, the approval marks the latest significant development in France’s baby steps towards restitution, which have been making slow progress for the past three years.

UPDATE: This article has been updated to reflect that the bill was passed on December 17, despite opposition from the Senate.