Election petition challenging his 2022 win: Mwago’s victory in Starehe was contested at the High Court in Election Petition No. E001 of 2022, with opponents alleging irregularities including bribery. In March 2023, the court upheld his election, finding that the poll had been conducted in line with electoral law and that the allegations were not proved; related documents also appear in IEBC and Gazette records.

Summons over alleged hate speech and ethnic contempt: In early 2025, the National Cohesion and Integration Commission (NCIC) reportedly summoned Mwago and other leaders over alleged inflammatory remarks, with some commentaries specifically accusing him of hate speech and ethnic contempt. Reports note that while some other politicians ignored the summons, Mwago complied and appeared before NCIC. As of November 2025, no formal sanction or conviction has been publicly reported.

Criticism for confrontational political rhetoric: His strongly worded attacks on President William Ruto, senior governors and the National Assembly Speaker—accusing them of divisiveness, bias or undermining Parliament—have attracted pushback from government allies, who frame his style as overly combative and populist, even as supporters describe it as principled oversight.

Debate over money in Nairobi politics: In an October 2022 interview, Mwago stated that he spent approximately KSh 50 million on his Starehe campaign and remarked that “Nairobi politics is about money,” sparking debate about the role of big spending and whether such costs shut ordinary citizens out of competitive races—even though no illegality was alleged.