CHICAGO (CBS) — A federal judge has denied former Cook County Commissioner William Beavers’ request to remain free on bond while he appeals his conviction on tax evasion charges.

U.S. District Judge James Zagel ruled Beavers has not shown his appeal is likely to result in a reversal, a new trial, or a sentence that spares him from jail. The ruling means, unless Beavers can convince a federal appeals court to give him an appeal bond, he must report to jail by Dec. 2, to begin his six-month sentence.

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Beavers, 78, was convicted in March of using his campaign fund as a his personal piggy bank, and spending more than $225,000 of campaign cash on personal expenses — including gambling sprees at the Horseshoe Casino in Hammond — without paying income taxes as required under federal law.

In September, Zagel sentenced Beavers to six months in jail, and imposed a $10,000 fine.

Beavers’ attorneys had argued he was not a flight risk, but Zagel ruled he must also show his “appeal raises a ‘substantial question of law or fact likely to result in’ a victory on appeal.”

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Defense attorneys had pointed to Zagel’s ruling that a tax expert for Beavers could not testify at trial.

However, Zagel ruled that expert’s testimony would have been based on what Beavers told him about his taxes, which would be hearsay, and not a valid basis to form an expert opinion. He also noted Beavers could have taken the stand himself to offer those statements to the jury.

Zagel also noted Beavers has not sought an expedited appeal, despite his looming jail sentence.

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The judge said an appeals court would be the best judge of whether Beavers’ chances for an appeal might be successful, and whether he warrants an appeal bond. He also said an appeals court could push back the date Beavers must surrender to custody.