Labour Union (Polish: Unia Pracy, UP) is a minor social-democratic[1][2][3] political party in Poland.

At the 2001 parliamentary elections, UP entered into an electoral alliance with the major Polish social-democratic party Democratic Left Alliance (SLD), and managed to get 16 of its members elected to parliament.

Some of those members subsequently left UP to join the newly created Social Democracy of Poland (SDPL), a splinter group from the SLD.

In May 2004, UP signed an alliance with SDPL, in which both parties agreed to jointly contest the following parliamentary elections under the SDPL banner, and to support the candidacy of Marek Borowski in the 2005 presidential election.

[5] In July 2015, the party joined the Zjednoczona Lewica (United Left) electoral alliance for the 2015 parliamentary elections.