In August 1997, he joined the firm of Martine Aubry at the Ministry of Employment and Solidarity as a technical advisor, then in 2000 the office of Lionel Jospin at Matignon.

In 2003, he found Martine Aubry in the urban community of Lille Métropole, as Deputy Director General of Services.

In June 2004, he married Anne Hidalgo, then deputy mayor of Paris, encountered Martine Aubry firm in 1993.

He supported Benoît Hamon in the second round of the primary citizen of 2017 and became co-director of his presidential campaign with MP Mathieu Hanotin.

Tout avait si bien commencé : journal d'un « frondeur », éditions de l'Atelier, 2015.