Zohran Mamdani, a socialist New York State Assembly member from Queens, will announce on Wednesday that he is entering the race to unseat Mayor Eric Adams, who is facing growing doubts over his political future.

Mr. Mamdani is the fifth prominent Democrat to challenge Mr. Adams, who was indicted last month on federal corruption charges. His administration has fallen into crisis, and many of his top aides have resigned.

Mr. Mamdani, who has called on Mr. Adams to resign, said in an interview that the mayor had failed New Yorkers. He said that he would focus his campaign on addressing the city’s affordability crisis.

“City Hall is engulfed in corruption, but it is the outrageous cost of living that most people are talking about,” he said. “New Yorkers are being crushed by rent and child care. Working people are getting pushed out of the city they built.”

In his campaign kickoff video, Mr. Mamdani proposes freezing rents on rent-stabilized apartments and targets both Mr. Adams and former Gov. Andrew M. Cuomo, who is considering running in the Democratic primary next June.