[5] ČSSD won the 2013 legislative election with 20% of the vote and formed a coalition government with ANO 2011 and Christian and Democratic Union – Czechoslovak People's Party.

The party suffered heavy losses in the 2017 election and finished in sixth place with 7% of the vote.

[6] In a subsequent leadership election, the main issue was whether ČSSD should join the new coalition government or be in opposition.

Milan Chovanec argued that the party should be in opposition, while Jan Hamáček and Jiří Zimola supported joining the coalition.

He also expressed the view that, as ANO 2011 was already working with the Communists and the far-right Freedom and Direct Democracy, he only needed ČSSD to legitimise his government.

[10] Sobotka eventually decided to leave politics, citing his opposition to coalition talks with ANO.

[12] Babiš offered the party only four cabinet positions, and refused to give ČSSD the Ministry of the Interior.

[16] Babiš then stated that a coalition of ANO, Freedom and Direct Democracy (SPD) and the Communists was the only option remaining.

Štěch noted that ČSSD had promised not to participate in a government led by someone facing criminal charges.

[27] Party leader Jan Hamáček originally refused to publish the names of the potential ČSSD ministers.

[34][35][36] Hamáček stated that he was not trying to convince members to vote to join the government, but to inform them about the agreement with ANO 2011.

[40] The Ústí nad Labem regional branch expressed its opposition to ČSSD participation in the new government.

Prague, Central Bohemia, Pardubice and South Bohemian regions voted in support of government participation.