The movement was founded after Kukiz stood in the 2015 presidential election, winning 21% of the vote and coming in third during the election's first round. Kukiz's primary issue during the election was the replacement of Poland's proportional representation electoral system with single member constituencies,[24][25] which was the subject of a referendum in September 2015.
The movement was particularly popular among young people: Kukiz won 42% among voters aged 18 to 29 in the 2015 presidential election.[26]
In the 2015 parliamentary election, Kukiz'15 cooperated with the far-right National Movement, which gained 5 of Kukiz' 42 parliamentary seats.[1][27]
In April 2016, the National Movement leadership decided to end its collaboration with Kukiz'15 and instructed its MPs to leave the Kukiz'15 parliamentary club, but only one MP followed party instructions.[28] These ones, who stayed in Kukiz'15, together with a few other Kukiz' MPs, formed National Democracy (Endecja).[29]
There was a Sejm scandal in April 2016. Kornel Morawiecki of Kukiz'15 left his Sejm member card in the voting device when he felt sick and went out from the debating hall and then Małgorzata Zwiercan voted for him. After this he left Kukiz'15 and launched a new party Free and Solidary (Wolni i Solidarni) along with two other Kukiz'15 MPs.
In February 2017, three Kukiz'15 MPs left the group and became a parliamentary representation of the association "Republicans" (Republikanie).
In February 2018, Paweł Kukiz apologised for having introduced the nationalists into the Sejm.[8]
In May 2018, Kukiz'15 has coordinated with the social conservative Right Wing of the Republic in local elections.[30]
In August 2019 Kukiz'15 joined the Polish People's Party (PSL) to set up a joint list for the 2019 parliamentary election named Polish Coalition. This alliance helped both parties overcome the 5%-threshold and Kukiz kept 6 MPs in the Sejm. Because of that alliance, the Real Politics Union ended cooperation with Kukiz'15.
However, the ideological differences between the Pro-European PSL and the Eurosceptic Kukiz MPs led to a quick fallout. In November 2020, a PiS motion was put to a vote on the support for the Polish government in the EU budget negotiations (in which Poland and Hungary used their veto). 5 of the 6 Kukiz MPs voted in support. This led the PSL and Kukiz'15 to part ways.[31]
On 20 June 2021, the reactivation of the congress of the Republicans, which were instrumental in the creation of Kukiz'15 in 2015, took place. Karol Rabenda announced that some Agreement members will join the Republican association and restructure it into a party, and that the newly formed party will subsequently join the governing coalition as a full member. In response, the Law and Justice chairman Jarosław Kaczyński made a speech praising the new reformed party.[32]
After Jarosław Gowin's scepticism with the "Polish Deal" proposal (an economic recovery plan for countering the COVID-19 recession in Poland) and media law changes that would inevitably force the American company Discovery, Inc. to sell its TVN Group, Gowin was publicly removed from his position as deputy prime minister, resulting in realignment of the composition of the coalition.[33] As result, Adam Bielan's "Agreement rebels" new party joined the coalition as replacements, and the remaining Kukiz '15 MP's led by Paweł Kukiz declared their support for the coalition, except Stanisław Tyszka.[34]