In a recent phone call, they say, he explained in vague terms why he wanted to go to trial first in District of Columbia federal court, where he faces related charges in a trial set for September.
Manafort is the former chairman of President Donald Trump's campaign.
Despite having griped about the conditions at Warsaw, and the distance, Manafort's lawyers had tried to get U.S. District Judge T.S. Ellis to reverse his order transferring him to the Alexandria jail.
Earlier this week, the judge had ordered that Manafort be moved from the Northern Neck jail, more than 100 miles away from his lawyers, to the Alexandria Detention Center near the courthouse.
Manafort, the former campaign manager for President Donald Trump, had asked for his July 25 trial on bank and tax-fraud charges to be delayed in large part because it was hard to prepare while incarcerated 100 miles away at a regional jail in Warsaw, Va.
On monitored prison phone calls, Manafort has said he's been treated like a "VIP," Mueller said.
Manafort, who was assigned an extra-large cell in his current jail, also has access to a separate workroom to meet with his attorneys from 8:30 a.m.to 10:00 p.m. Visitor logs from the jail show that each week Manafort had multiple visits with his legal team, according to Mueller's filing.
Manafort has even used a workaround, prosecutors allege, to send more emails to outsiders: He "reads and composes emails on a second laptop that is shuttled in and out of the facility by his team".
According to the prosecution's filing, Manafort had enjoyed numerous "unique privileges" at the Virginia facility including access to his personal laptop and telephone. Instead, a judge chose to move Manafort into more a more traditional jail situation, though he will be kept separate from other inmates for his own safety.More news: Nirbhaya rape case: Amnesty says executions don't eradicate crime against women
A hearing on Manafort's request for the trial delay is scheduled for July 17.
In a rebuttal, Manafort's lawyers said the effort put into monitoring their client's phone calls showed that Mueller had "unlimited resources" and accused his office of choosing conversations "to support its version of events".
Ellis concluded that Manafort's ability to prepare for trial "trumps his personal comfort". They claimed they needed more time to prepare their defense, and they pointed to the location of Manafort's jail as part of the problem.
The special counsel said Manafort's actions violated federal law, and therefore violated the terms of his pretrial release.
Prosecutors said most of the documents handed over recently are from Manafort's own bookkeeping service and are not unfamiliar to him. Manafort has pleaded not guilty to all charges.
"The five previously charged counts against Manfort remain unchanged: conspiracy against the United States, conspiracy to launder money, unregistered agent of a foreign principal, false and misleading FARA [Foreign Agents Registration Act] statements, and false statements", the special counsel's spokesman said last month.
"Manafort can hardly now complain about the order of the trials", the special counsel's attorneys said.