SPRINGFIELD, Ill. – A former teachers union lobbyist is suing Illinois’ state retirement board in an attempt to force a special pension deal he received for serving one day as a substitute teacher.

Retired Illinois Federation of Teachers lobbyist David Piccioli, 65, wants the state’s Teachers Retirement System to honor a sweetheart deal he received through special legislation in 2007 that allowed him to apply his time as a lobbyist toward a teacher’s pension, the Chicago Tribune reports.

That law, signed by then Gov. Rod Blagojevich, allowed Piccioli and another union lobbyist, Steven Preckwinkle, to apply their time with the union toward a pension with the Teachers Retirement System after serving only one day as substitute teachers in Springfield.

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“After the Tribune and WGN-TV reported on the pension maneuvers, legislators passed a bill aimed at scaling back the lobbyists’ benefits. Piccioli is now arguing that 2012 law should be declared unconstitutional and voided,” according to the news site.

Carl Draper, Piccioli’s attorney, told the Tribune the case rests on a provision in the Illinois Constitution that prohibits pensions from being “diminished or impaired” once they’re in place. It’s the same provision that’s at the heart of another case in the Illinois Supreme Court last week in which public employee unions are seeking to block a law designed to curtail the state’s $100 billion in pension debt.

“It’s bold and it’s unfortunate given the image that that gives about people who are receiving public pensions,” state Sen. Kwame Raoul, sponsor of the 2012 legislation, said of Piccioli’s lawsuit. “That’s not characteristic of the common, hardworking public-sector worker who makes a modest income and has a modest retirement benefit. It gives people the impression of otherwise.”

Piccioli currently collects $31,485 per year from the Teachers Retirement System, but that figure could increase by another $36,000 if he wins his case and is able to apply all of his time in the teacher’s union toward retirement.

The Teachers Retirement System payout is in addition to another $30,000 pension through the State Employees Retirement System that Piccioli “earned” while serving as a legislative aide in the 1990s.

The lawsuit involves a complex formula for calculating pensions in the Teachers Retirement System that includes purchased credits.

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The Tribune explains:

The law allowed Piccioli and Preckwinkle to enter the Teachers Retirement System by spending one day teaching before the law was enacted, and it allowed them to count their work with the Illinois Federation of Teachers toward a pension.

Piccioli later bought retroactive pension credits so his prior service with the union would count toward his benefits. Preckwinkle did not buy such retroactive credits. But for both lobbyists, time spent in their union jobs after their one day of teaching would help boost their pensions.

The later law, which Quinn signed in January 2012, revoked the lobbyists’ ability to put their earlier years with the union toward their pensions.

Piccioli was refunded the retroactive time he purchased in the Teachers Retirement System – $192,668 plus $34,319 in interest – and his current payout is based on the roughly six years he worked for the union after the 2007 law, as well as accumulated unused sick leave, the Tribune reports.

“Pensions in the teacher system are based on a formula that includes the number of years of service and an average of the four highest consecutive years of salaries in the last 10 years that a person works. For Piccioli, those four years ranged from about $151,000 to nearly $204,000, according to the system.”

If he wins the lawsuit, Piccioli will be able to apply the 10 years he worked with the union prior to his one day of substitute teaching, which would push his total public pension to more than $97,000 per year.