SAN FRANCISCO, June 10 (Reuters) - California's government is 50 days away from a financial "meltdown" in light of weakening revenues in May unless Governor Arnold Schwarzenegger and lawmakers quickly plug a $24.3 billion budget gap, the state's controller said on Wednesday.

Controller John Chiang, who has previously warned that California risks running out of cash without a budget deal, said revenues in May fell by $1.14 billon, or 17.7 percent, from a year earlier. The revenues fell short of estimates in Schwarzenegger's budget plan by $827 million, he said.

"Without immediate solutions from the governor and legislature, we are less than 50 days away from a meltdown of state government," Chiang said in a statement. "A truly balanced budget is the only responsible way out of the worst cash crisis since the Great Depression." (Reporting by Jim Christie; Editing by Leslie Adler)