Illinois' credit standing took another hit on Monday as Fitch Ratings downgraded the state's rating for the first time on Governor Bruce Rauner's watch, citing the deterioration of state finances during a four-month budget impasse. Illinois has no budget yet for the fiscal year that began on July 1, and the stalemate between Republican Rauner and Democrats who run the legislature has taken a bite out of state services. The downgrade is the most potent sign yet that it is worsening the state's already precarious standing on Wall Street. The one-notch downgrade from A-minus to BBB-plus, affecting $26.8 billion of general obligation bonds, leaves Illinois as the only U.S. state with a rating in the low investment grade triple-B level. Fitch has previously dropped only California to that level in 2003 and 2009, according to Karen Krop, a Fitch analyst.

Ilinois governor Bruce Rauner. Getty Images

Rauner's administration minimized the significance of the downgrade, the first since he took office in January, blaming Democratic legislators who have stymied his attempts to include business-friendly reforms in the budget. "Fitch points out that the Illinois economy lags other states' and has major structural challenges," Rauner spokeswoman Catherine Kelly said in a statement. "Governor Rauner continues to fight for structural reforms that will put the state on a path to fiscal health, but the legislature continues to protect the failed status quo." Senate President John Cullerton, a Chicago Democrat, called on Rauner to drop his "corporate class agenda." "This lowered credit rating is just one way that we can calculate the true cost of doing business the Rauner way," said Cullerton spokeswoman Rikeesha Phelon. "It's time to hit the reset button and move toward a resolution." Rauner's top political nemesis, Democratic House Speaker Michael Madigan, said it is time to focus solely on a state budget. "The lack of a resolution on the state budget and today's downgrade are direct results of the governor's continued focus on issues other than solving our budget crisis," Madigan said in a statement. More downgrades possible Illinois' last bond sale was in May 2014. The governor's office has said the state intends to return to the U.S. municipal bond market this fiscal year. Illinois continues to pay a hefty market penalty for its fiscal woes, which include the worst-funded pensions among the 50 states. Its so-called credit spread over Municipal Market Data's benchmark yield scale for AAA-rated debt has widened from 140 basis points at the beginning of 2015 to 190 basis points on Monday.