France began collecting its 2025 population census data on Jan 16, a process that will end on March 8 and one that has angered critics because of a controversial new question.

This year's census will gather comprehensive demographic data through both online and paper questionnaires and more than 9 million residents and 5 million households across the country are expected to participate.

For the first time, the census will include dual nationals, a notable change from previous practice and a question about parents' origins.

Conducted by the French National Institute of Statistics and Economic Studies, or Insee, the census is essential for shaping public policies. It aids government funding, urban planning, and regional inequality assessments.

Sylvie Le Minez, head of demographic studies at Insee, explained on the institute's website that "the census helps us understand population diversity, measure inequalities, and sometimes identify discrimination".

Despite its significance, the 2025 census has ignited debate due to a new optional question in which participants are asked about their parents' birthplace. Critics argue that this could lead to discrimination, contravening constitutional principles of equality.

A coalition of organizations, including the Human Rights League, or LDH, and trade unions, published a petition and opinion piece on the online newspaper Mediapart, urging citizens not to answer the controversial question.

Nathalie Tehio, president of the LDH, and Sophie Binet, secretary-general of the General Confederation of Labour, cautioned: "No public policy justifies collecting information about the immigrant origins of our parents. This question is dangerous."

By Monday, the petition had garnered more than 2,900 signatures.

France's strict data privacy laws and constitutional principles forbid the use of racial or ethnic classifications in official records.

A 2007 ruling by the French Constitutional Council affirmed: "The Republic ensures equality before the law for all citizens without distinction of origin, race, or religion."

However, anonymized demographic data based on nationality or geographic origin is allowed for research and statistical purposes.

Nonetheless, skepticism persists. In their Mediapart article, Tehio, Binet and others expressed concern that the data could facilitate unequal treatment, and potentially be misused by future governments.

Marcus Alexandre, a 56-year-old restaurant owner in Courbevoie, a city in the Greater Paris region, said: "I believe this question will help us understand our community's roots and improve services such as employment and social statistics."

In contrast, Thibault Julien, a 46-year-old baker from Puteaux in Greater Paris, disagreed. "I don't see the point," Julien said. "Why is the birthplace of parents necessary for the census? It could lead to discrimination in society — something the far right has pushed for years."

In pilot tests, 4 to 5 percent of participants found the question problematic, often due to not knowing their parents' origins. Insee made the question voluntary in response to these concerns.

The writer is a freelance journalist for China Daily.