Parti Socialiste Vannois
|Founded||June 8, 1932|
|Dissolved||3 May 2025|
|Succeeded by||Parti National Libéral|
|Headquarters||72 Rue de l'Espoir, Libéliard, Antiyonne-Grenoît, Vannois|
|Student wing||Mouvement socialiste étudiants|
|Youth wing||Mouvement des jeunes socialistes|
|Ideology||Social Democracy Democratic Socialism|
|International affiliation||Socialist International|
|Slogan||Le changement est maintenant|
|Chambre des Pairs|
393 / 924
|Chambre des Répresentants|
418 / 794
The Parti Socialiste also known as the Socialist Party or Social Democrats, was the most powerful left-wing political party in the Vannoisian Empire. The party was constantly trading places with either of the Alliance Centriste or Union pour un mouvement populaire. It grew out of the trade union movement and socialist political parties of the early nineteenth and late eighteenth centuries and has been described as a broad church; the party contains a diversity of ideological trends from strongly socialist, to more moderately social democratic.
As of 2024 it was the largest party in the Chambre des Répresentants with 418 CdRMs, ahead of the UMP's 262. Following the dissolution of the Unité coalition and François Jauffret's resignation as party leader, David Vasseur led the party through the 2024 snap elections and as Prime Minister.
The Party was founded in 1932 following the dissolution of les Communistes de Vannois and the original Socialist party by then-Emperor Francis III. It was created in Libéliard by the Socialist philosopher Arsène Flandin, and formed around the Lord Jean-Jacques Viermont, Count Migor. The party was rebranded as Parti National Libéral in 2025.