Proposed legislation in Richmond that would require Fairfax County to have an independent auditor for the county schools has sparked vigorous debate about how the state’s largest school system handles its budget.

The bill — sponsored by Del. Mark Sickles (D), whose 43rd District includes parts of Fairfax County — aims to reduce spending and find savings in the school system’s $2.5 billion budget. Sickles said he believes that an independent auditor is necessary to help the schools run more efficiently.

“We just want to make sure that when you have an organization that vast, that there is an independent look at how things are operating,” Sickles said, noting that in years past, the school system has ended the fiscal year with tens of millions of dollars left unspent.

The bill is scheduled to be discussed during a subcommittee meeting Wednesday, and it comes at a tense time for the School Board and its county counterparts, the Board of Supervisors, who allocate tax dollars to the schools. Superintendent Karen Garza has asked the Board of Supervisors for an extra $98 million in county funds for next year’s budget, an amount supervisors said is unrealistic because county funds are tight.

For years, supervisors have lobbied the schools to create a more independent auditing function. Some supervisors have said that the schools could receive more funding each year if an independent auditor’s office existed.

“The Fairfax County Board of Supervisors has found the independent analysis that the auditor of the Board brings to be very helpful in improving the quality of the County’s financial management and operations,” said Sharon Bulova (D), chairman of the Board of Supervisors. “While the county has not taken a position on Del. Sickles’ bill, I believe the School Board would benefit from an auditor in a similar fashion.”

Supervisor Jeff C. McKay (D-Lee) said that the county’s auditor has helped the county save millions of taxpayer dollars.

“I will say it just seems to me crazy that an organization of that size doesn’t have an independent auditor,” McKay said of the schools. “It would go a long way to build trust with the public.”

The bill by Sickles would create the position of independent auditor, which would report findings to the Board of Supervisors, forcing the schools to speed a process underway to improve its auditing abilities. The school system has had an internal auditor for years, said Daniel G. Storck (Mount Vernon), chairman of the School Board’s audit committee. In December, the board voted unanimously to add two new positions in the schools’ audit office, Storck said.

Storck said plans are to hire an “auditor general” this summer. That person would report to the School Board. “The bottom line is we have an independent function now, but we recognize that we need to improve it and broaden its scope,” Storck said.

Sickles said the School Board’s move to have its finances audited is “coming along” but has been too slow. “They don’t have independent ways to look at their performance,” Sickles said.

The bill caused immediate consternation among members of the School Board.

“This is an unwelcome meddling in the challenging, but mostly successful, relationship we work very hard to maintain” with the supervisors, School Board member Pat Hynes (Hunter Mill) wrote to delegates. Hynes also wrote that the bill “would be a resounding and wholly unwarranted vote of no confidence in our School Board.”

Sickles said Tuesday that he plans to offer a substitution to his bill that would remove the language referring to the supervisors’ role in the independent auditing process. Sickles said the substitution would call on the School Board to appoint an independent auditor to help “reduce expenditures and otherwise improve the efficiency and effectiveness of the resources of the school division.”

Del. Scott A. Surovell (D), whose 44th District also includes Fairfax and who is on the subcommittee considering the bill, called the measure a “distraction” from the real issue: school funding.

“The Board of Supervisors continues to come up with excuses for why they won’t appropriate sufficient money to fund a world-class education system in the county,” Surovell said.