The deal with AFSCME calls for cutting state costs with furlough days and employees paying higher insurance costs.
Quinn's Republican challenger for governor, Bill Brady, is condemning the agreement.
Brady calls it scandalous and describes it as another secret deal with more than a whiff of impropriety.
Governor Quinn negotiated with the union and then got an endorsement. He said the deal was not party to politics, but was borne of financial necessity, and said it means the people win.
"We think it's unconscionable," said Brady. "This smacks so much of pay-to-play, and it's scandalous."
Bill Brady and Pat Quinn made a joint appearance Tuesday at the Chicago Club. Cameras were not allowed, but both took their fight outside.
"There's always give and take in negotiations, but sometimes the governor has to do tough things to save money for the public, and that's what I've done," said Quinn.
What the governor has done is strike a tentative agreement with the state's largest employee union, AFSCME.
The union has agreed to defer scheduled wage increases, encourage voluntary furlough days and make health care changes for roughly 40,000 state workers.
That could save the state $150 to $200 million. In return, the governor guaranteed that there would be no AFSCME layoffs and no state facilities where AFCSME workers are employed would be closed through June 2012.
"Let's let this election play out, the next governor manage the state resources with the flexibility he needs without some contract that was put together with the timing of an endorsement," said Brady.
Shortly after the tentative agreement was reached last week, AFSCME endorsed Quinn for Governor, and that Brady says is a scandal of Blagojevich proportions.
"That's a lot of baloney obviously, from somebody who knows all about baloney," Quinn said.
Quinn says there's no link between a political endorsement and an agreement needed to save the state money. Collective bargaining agreements, he says, are not structured to run concurrent with election cycles.
AFSCME officials say an original agreement calling for pay raise deferrals and furlough days started earlier this year, before the primary, when the union refrained from an endorsement in the governor's race.
"I'm sure no matter what time it occurred... once it was election season, I'm sure Senator Brady would have the same objection," said AFSCME Associate Director Mike Newman.
The tentative agreement between AFSCME and the governor, while not yet completely finalized, forecasts a range of cost savings.
The agreement is dependent on wage increase deferrals, which are locked in, furlough days, which are voluntary, and a host of other suggested cost cutting from the union.
Brady objects that the process has not been transparent, hat it carries an odor of deal-making, and that it is not wise to make a no-layoff, no-closing guarantee.