Mazurek worked as the deputy to Kotleba MP Andrej Medvecký, and took over his mandate after Medvecký's subsequent resignation (a week after the 2016 Slovak parliamentary election) for having been charged with a racist assault of a Dominican citizen. At this time, Mazurek attracted media attention for shouting vulgar insults at an Arab family at an anti-Islam rally and for praising Adolf Hitler on social media.[3][4] He was investigated by prosecutors for other posts denying the Holocaust, which is a crime in Slovakia.[4]
In an October 2016 speech on Rádio Frontinus [sk], Mazurek said "The Gypsy anti-socials have never done anything for the nation and never will," comparing children of Romani ethnicity to "animals in the zoo".[5][6]
In 2018, the Specialised Criminal Court convicted him under Article § 423 of the Penal Code, which prohibits "defamation of the nation, race, and belief", and fined him 5,000 euros. Mazurek appealed to the Supreme Court of Slovakia, which ruled on the case in September 2019 and upheld the sentence, increasing the fine to 10,000 euros.[6] He paid the fine, making him eligible to run in the 2020 election.[7]
Following the Supreme Court's verdict, former prime minister Robert Fico recorded a Facebook video in which he said, "Milan Mazurek said what almost the whole nation thinks and if you execute someone for truth, you make him a national hero". Fico is now being investigated for promoting racism.[8][5] ĽSNS put up many billboards stating "Milan Mazurek, fired from parliament for expressing an opinion".[8]
As a result of his conviction, Mazurek lost his seat in parliament in September 2019 due to the Constitution of Slovakia,[9] becoming the first Slovak MP to lose his seat due to a crime.[6] He was eligible for two-month severance pay and immediately hired as a parliamentary secretary for People's Party Our Slovakia, earning 2,700 euros per month.[7] After losing his seat in parliament, Mazurek was replaced by Milan Špánik, an independent regional politician who won his seat with Kotleba's support.[6]
He refuses to wear a mask during the COVID-19 pandemic due to a false belief that it would cause carbon dioxide poisoning,[13] which led to his being thrown out of a bank in Poprad.[14] In July 2020, he faced calls for his resignation after falsely claiming that the perpetrator of the Vrútky school attack [sk] was of Romani ethnicity.[15]