Attorneys for Manafort argued that Rosenstein overstepped his authority in May 2017 when he appointed Mueller as special counsel to investigate "links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump" and "any matters that arose or may arise directly from" that investigation.
The scope of the investigation is overly broad, Manafort’s attorneys argued, asking a judge to set aside both the October indictment and Rosenstein’s appointment of Mueller.
"The actions of (the) DOJ and Mr. Rosenstein in issuing the Appointment Order, and Mr. Mueller's actions pursuant to the authority the Order granted him, were arbitrary, capricious, and not in accordance with the law," the suit said.
Manafort and his former business associate, Rick Gates, were indicted in October on 12 charges. In the 31-page indictment, federal prosecutors accused Manafort and Gates of conspiring against the United States, conspiring to launder money and working as unregistered foreign agents.
Both Manafort and Gates have pleaded not guilty.
Authorities said the alleged events took place between 2006 and "at least 2016." However, attorneys for Manafort said in his lawsuit that the activities ended in 2014 and that the Justice Department was aware of them before he was indicted.
Attorneys said Manafort met with federal prosecutors and FBI agents on July 30, 2014, as part of an investigation into the activities of a former Ukrainian president.
"During the interview, Mr. Manafort provided a detailed explanation of his activities in Ukraine, including his frequent contact with a number of previous U.S. Ambassadors in Kiev and his efforts to further U.S. objectives in Ukraine on their behalf," Manafort's attorneys said. "He further discussed his offshore banking activity in Cyprus.
"The indictment does not charge any links between Mr. Manafort and the Russian government. Instead, the special counsel has constructed an indictment that, at its essence, concerns failing to file certain information reports of offshore bank accounts and failing to register as a foreign agent. None of the charges relate to Mr. Manafort's activities during his brief stint in 2016 as the campaign manager for the Trump presidential campaign."
Manafort joined the Trump presidential campaign team in March 2016 and served three months before he was forced to resign amid reports that his firm was involved with covert lobbying in support of a pro-Russian political party in the Ukraine, The Associated Press reported.
In a statement released to BuzzFeed News, a DOJ spokesperson called Manafort's suit "frivolous."