Lawyers for Paul Manafort, President Trump's former campaign chairman, say their client has been in solitary confinement as he awaits trial on financial charges.

The lawyers say Manafort is locked in a jail cell in Virginia for 23 hours a day and has been in solitary confinement because the facility can't guarantee his safety.

Manafort was jailed last month after a federal judge revoked his house arrest over allegations of witness tampering in special counsel Robert Mueller's investigation. Manafort had been on house arrest, but his circumstances changed with a judge determined he had violated the terms of his pre-trial release. When Manafort was in court to face superseding charges accusing him of witness tampering — charges to which he pleaded not guilty — Judge Amy Berman Jackson said she didn't feel she could draft an order broad enough to include any potential future violation.

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"This is not middle school, I can't take away his cellphone," she said in court.

Manafort's lawyers are asking a federal appeals court to overturn the judge's order and release him under certain conditions as he awaits trial later this month in Alexandria, Virginia, and later in Washington, D.C. They say his detention makes it "effectively impossible" for Manafort to prepare for trial.

Mr. Trump has distanced himself from Manafort, saying the man didn't work on the campaign long. But he's also called the charges against Manafort "very unfair."

"Well, I feel badly about a lot of them, because I think a lot of it is very unfair," Mr. Trump said outside the White House last month. "I mean, I look at some of them where they go back 12 years. Like Manafort has nothing to do with our campaign. But I feel so -- I tell you, I feel a little badly about it. They went back 12 years to get things that he did 12 years ago?"

"You know, Paul Manafort worked for me for a very short period of time. He worked for Ronald Reagan. He worked for Bob Dole. He worked for John McCain, or his firm did. He worked for many other Republicans. He worked for me, what, for 49 days or something? A very short period of time."