Illinois already has an A3 rating with a negative outlook from New York-based Moody's, the lowest of any of the 50 states, and in a statement today the firm warned that the new budget, unless changed, could force the state to "rely on credit-negative practices." Moody's specific concern is that, by failing to renew the 2011 income tax hike that's scheduled to begin sunsetting on Jan. 1, lawmakers punched an estimated $1.8 billion hole in the budget for the fiscal year that begins Jan. 1. Unless the state generates more revenue and/or cuts spending, the state's backlog of unpaid bills may rise, Moody's said, "reversing significant progress of recent years." The backlog had dropped to about $5.6 billion from a peak of $9.9 billion in 2010, Moody's said. "Renewed growth in the backlog could put financial pressure on rated entities, such as public universities awaiting payment from the state," it said, suggesting that Illinois faces a growing "structural deficit."