The highly unusual lawsuit says the special counsel, Robert S. Mueller III, was given an overly broad mandate and needs to be reined in.
WASHINGTON — President Trump’s former campaign chairman, Paul Manafort, sued the special counsel on Wednesday and asked a federal court to narrow his authority, escalating Republican efforts to discredit an investigation that has stretched longer than the White House expected.
The unusual move comes as Mr. Trump tries to portray the investigation as a politically motivated witch hunt that has cast a dark cloud over his administration and, in his view, the country.
The president said last week that he hoped the special counsel, Robert S. Mueller III, will treat him fairly. Mr. Trump’s lawyers have advised against directly criticizing Mr. Mueller, a Republican who is regarded as one of the premier law enforcement officials of his time. But with four former Trump campaign aides facing charges and no end to the investigation in sight, some of Mr. Trump’s allies have stepped up their attacks.
Mr. Mueller is investigating the Russian government’s meddling in the 2016 presidential election and whether anyone close to Mr. Trump was involved. As part of that investigation, prosecutors indicted Mr. Manafort on money laundering charges related to years of foreign lobbying — but not related to Russian election interference or the Trump campaign.
Mr. Manafort argued in the lawsuit that Mr. Mueller had gone too far. He sued both Mr. Mueller and Rod J. Rosenstein, the deputy attorney general who appointed Mr. Mueller. The lawsuit said Mr. Rosenstein had improperly given Mr. Mueller the authority to investigate “anything he stumbles across while investigating, no matter how remote.”
A spokesman for Mr. Mueller had no comment on the lawsuit.
The charges against Mr. Manafort date back years, well before he began working for Mr. Trump. His lawyers argue those charges exceed Mr. Mueller’s jurisdiction because he was authorized only to investigate separate matters if they arose from the Russia investigation.
That theory echoes comments made by Mr. Trump, who has said that Mr. Mueller cannot investigate his family’s personal finances.
Mr. Manafort asked a federal judge to reject Mr. Mueller’s appointment as overly broad and to dismiss the indictment against him. He also asked that an order be issued that would prohibit Mr. Mueller from investigating anything beyond Russian meddling in the election.
Mr. Mueller served as F. B. I. director under Presidents George W. Bush and Barack Obama. He is credited with refocusing the F. B. I. on counterterrorism after the Sept. 11,2001, attacks.
Mr. Trump has said he has no plans to fire Mr. Mueller, but he and his allies have repeatedly tried to disparage his investigation.
