A federal grand jury indicted Manafort and his business associate Rick Gates in October as part of Special Counsel Robert Mueller's investigation into accusations of Russian meddling in the 2016 U.S. presidential election, as reported by Reuters.
The charges against Manafort include conspiracy to launder money and failing to register as a foreign agent working on behalf of former pro-Russian Ukrainian President Viktor Yanukovych's government, who was ousted in 2014.
Thursday's filing came after prosecutors working for Mueller said earlier this week that they no longer could agree to more lenient bail terms for Manafort after discovering that he was working with a colleague tied to Russian intelligence agencies on an opinion piece that cast his work in a favorable light.
Mueller's office argued that his efforts to work behind the scenes on the piece as recently as November 30 ran afoul of the judge's November 8 order instructing all parties to refrain from making statements to the media or in public settings that could prejudice the case.
Jason Maloni, a spokesman for Manafort, declined to comment. Joshua Stueve, a spokesman for Mueller, also declined to comment.
Downing said in Thursday's filing that his client was involved only in editing the piece to ensure accuracy and that it would not prejudice the case because it was ultimately published in a Ukrainian newspaper, not an American one.
"The defense did not, and does not, understand that the court meant to impose a gag order precluding Mr. Manafort from addressing matters, which do not 'pose a substantial likelihood of material prejudice to this case,'" Downing wrote.
Read alsoManafort tried to pen positive op-ed on Ukraine work: special counsel – mediaEarlier in the week, prosecutors said in a filing that they had reached out to Manafort's lawyers when they discovered the draft and had been assured that it would not be published.
The piece appeared online in the English-language Kyiv Post on Thursday.
The article, which was authored by Oleg Voloshyn, a former spokesman for Ukraine's foreign affairs ministry, praised Manafort's political work in helping Ukraine secure better relations with the European Union.
"I can only wonder why some American media dare falsely claim that Paul Manafort lobbied Russian interests in Ukraine," the piece said. "Without his input Ukraine would not have had the command focus on reforms that were required to be a nation candidate to the EU."
Brian Bonner, the chief editor at the Kyiv Post, told Reuters that the article was submitted on Monday.
Bonner said Voloshyn claimed to have written the article and then sent it to Manafort and the American's longtime Russian colleague, Konstantin Kilimnik, for fact-checking before submission.
Bonner said he did not immediately publish the article because he was suspicious of the contents and wanted to confirm that Voloshyn had written it.
"It was blatantly pro-Manafort with an opinion about his activities that most people don't share and that his record in Ukraine doesn't support," Bonner wrote in an email.
Voloshyn told Reuters he was not immediately in a position to comment.
It was not clear when U.S. District judge Amy Berman Jackson would decide the issue, but Manafort and Gates are due to appear before her on Monday in the U.S. District Court for the District of Columbia for a status hearing.