Social Democratic Union of Workers and Smallholders (Finnish: Työväen ja Pienviljelijäin Sosialidemokraattinen Liitto, TPSL) was a political party in Finland.

[1] Leskinen wanted to co-operate with the right wing, based SDP politics on the general population, and his economic policy was conservative and deflatory, and he criticised agricultural subsidies.

In contrast, Skog's fraction wanted to co-operate with the agrarians and other leftists in popular front governments (kansanrintamahallitus), and base their politics exclusively on the trade unions.

For example, Heikki Laavola has written that the disagreement was not over left vs. right ideology; all of Tanner, Leskinen, Skog and Simonen had been formerly active in anti-Communist pursuits.

Significantly, TPSL co-operated with the especially powerful President Urho Kekkonen, and was a partner in coalition cabinets (Karjalainen I, Paasio I, Koivisto I).