Inactive or defunct Union of Left Forces (Ukrainian: Союз лівих сил, romanized: Soyuz livykh syl; SLS) was a political party in Ukraine led by Vasyl Volha from its founding in 2007 to 2019.

[13] The party participated in the 2010 Ukrainian presidential election as part of the Bloc of Left and Center-left Forces and supported Petro Symonenko as this bloc joint candidate for the post of President of Ukraine at the 2010 Ukrainian presidential election.

On 18 February 2022, in the prelude to the 2022 Russian invasion of Ukraine, Holdarb appealed through the US and UK embassies to the leadership of these countries "to compensate for the damage caused to our economy due to the military panic inspired by them".

Union of Left Forces is a socialist party,[6] although political observers note the highly left-wing populist character of it.

It is a staunch opponent of decommunization laws implemented by the Ukrainian government, which was used to prohibit and take down all symbols associated with the Soviet Union and communism.

[8] A unique proposal of the party is to create a "common security space" which would include both Russia and the European Union that Ukraine could be a part of.