[5] In June 2019, La République en marche announced its support for Laurent Degallaix for the 2020 municipal elections in Valenciennes.

[15] A supporter of Alain Juppé in the 2016 open Right and Center primary, he rallied to Emmanuel Macron's candidacy for the 2017 presidential election,[16] but did not provide his sponsorship.

[17] Affected by the law on the accumulation of mandates, he does not seek re-election in the following legislative elections but becomes the deputy substitute for Béatrice Descamps.

[18] Laurent Degallaix ran in the 2021 departmental elections in the canton of Valenciennes as a pair with senator Valérie Létard, against outgoing The Republicans (LR) councillors Yves Dusart and Geneviève Mannarino, whom he described as "interims ".

[21] The same year, after the de facto demise of the MR, he joined the Horizons movement created by former Prime Minister Édouard Philippe.