He was député for the third constituency of Seine-et-Marne in the National Assembly from 2002 to 2018, Mayor of Montereau-Fault-Yonne since 1995, and president of the Communauté de communes des Deux Fleuves.

He is also founder and president of a local party Mieux Vivre Ensemble (MVE), formerly known as Mouvement des Seine-et-Marnais (MdSM).

[3] As of early 2023, he is the executive director (Délégué Général) of the Avec financial group, which is under investigation for alleged illegal asset stripping.

Electoral mandates While most members of the French parliament are also mayors or general (department) or regional councillor,[5] Jégo is one of the few to cumulate three elected offices.

But giving as a pretext a legal complaint from the Front National's candidates, he still held the three of them, plus his local mandate of president of the « communauté de communes des deux fleuves » (CC2F) until his resignation from the Regional Council in July 2011.