Imprisoned former Illinois Gov. George Ryan is seeking to have elements of his conviction thrown out based on a U.S. Supreme Court ruling that sharply curtailed an anti-fraud law employed by prosecutors nationwide to convict politicians and executives.

The Illinois Republican becomes the latest public figure to challenge convictions based on the disputed provision. He joins former newspaper magnate Conrad Black — who was freed on bail as he appeals his fraud conviction — and the former CEO of disgraced energy giant Enron, Jeffrey Skilling.

The hope, Ryan attorney Jim Thompson said Wednesday, is that the move will result in the 76-year-old's release soon from a federal prison in Terre Haute, Ind. Ryan is serving a 6 1/2-year sentence and was expected to be released only in 2013.

In a filing with the U.S. District Court in Chicago late on Tuesday, Ryan's attorneys cited the Supreme Court's June decision focusing on Skilling's case. The justices voted to keep the so-called honest services law in force, even as they joined unanimously in weakening it.

Six attorneys spent months poring through the high court's ruling before deciding to ask federal Judge Rebecca Pallmeyer — who presided over Ryan's 2006 trial — to toss the convictions, said Thompson, himself a former Illinois governor.

"Skilling applies here. There's no question about it," he said.

At his tumultuous six-month trial, Ryan was convicted of racketeering, conspiracy, tax fraud and making false statements to the FBI when he was secretary of state and later governor from 1999 to 2003.

Not all Ryan's convictions, including lying to the FBI, are tied to honest services laws, which bar public officials from denying taxpayers their honest services. The filing in Chicago seeks only to have convictions linked to such laws overturned.

The provisions have been criticized by defense lawyers as far too vague and a last resort of prosecutors in corruption cases that lack the evidence to prove that money is changing hands. But watchdogs consider it key to fighting white-collar and public fraud.

The filing asks that Ryan be released on bond pending a ruling on Tuesday's motion. And if Pallmeyer agrees to strike the convictions related to honest services altogether, the filing says Ryan should be allowed to go free based on the time he's already served.

Current Gov. Pat Quinn, for one, didn't want to see Ryan let out early.

"If you do the crime, you gotta do the time," he told reporters Wednesday.

Thompson argued that Ryan has already served time on convictions not affected by the Supreme Court ruling.

"He has done the time for the crimes he committed," Thompson said. "But I don't think Gov. Quinn thinks he should be serving time under an unlawful law."

At Ryan's trial, prosecutors presented evidence that thousands of dollars in bribes paid in exchange for commercial driver's licenses ended up in Ryan's campaign fund. They also claimed that when state investigators from the office of the Secretary of State's inspector general began to look into the payoffs and the campaign fund, Ryan had his aides dismantle the inspector general's office.

The filing is the latest of several attempts by Ryan to avoid prison and then to get out once he was behind bars. Just before he was due to start his sentence, U.S. Supreme Court Justice John Paul Stevens refused an urgent request to grant him bail. And Ryan's wife, Lura Lynn Ryan, wrote letters to President Barack Obama and then-President George W. Bush seeking clemency for him.

The honest-services ruling also came up at the recent trial of Ryan's successor as governor. Defense attorneys for former Democratic Gov. Rod Blagojevich cited it in their bid for a mistrial. But Judge James Zagel rejected that, saying the court's decision had no major impact on Blagojevich's case.

Blagojevich's trial ended last month with a conviction on just one out of 24 counts — lying to the FBI. He is expected to be retried on the remaining charges early next year. He is appealing the one conviction and has pleaded not guilty to the other counts, including scheming to sell or trade Obama's old Senate seat and to racketeering.

Black was recently freed on bail from a federal prison after serving about two years of a 6 1/2-year sentence for defrauding Hollinger International Inc. investors. One argument prosecutors made was that Black deprived the company of his faithful services as a corporate officer. When the Supreme Court limited the scope of the honest services law, a court granted Black bail as he appeals his fraud conviction.

Pallmeyer could free Ryan within weeks, at least while his motion is pending, said former federal prosecutor Jeff Cramer.

"There's always a hope for him," he said. "Black got out pending arguments, and Ryan's sentences were similar in years." Cramer added that any final decision was difficult to anticipate given the complexities of the case.

Randall Samborn, a spokesman for the U.S. attorney's office, said prosecutors would not comment on the Ryan filing.


Associated Press Writer Deanna Bellandi contributed to this report.