Every year, Prince William County gives each member of the Board of County Supervisors hundreds of thousands of dollars, which they use to hire staff and pay for routine office expenses such as stationery and pens.

But the business of governing in Prince William generally costs less than the county’s allowance, which ranges from $358,000 to $408,000, depending on the supervisor. In many cases, there is money left over — sometimes thousands of dollars.

Those funds don’t get returned to the county’s general fund or to taxpayers. Instead, the supervisors use the funds to donate money to schools, charities, nonprofit groups, youth leagues, the arts and other organizations.

For years, critics have said the spending accounts — the only ones of their kind in Northern Virginia — allow the supervisors to generate not only goodwill but also name recognition on the public’s dime. Under a proposal offered by freshman Supervisor Peter K. Candland (R-Gainesville) that is expected to be taken up Tuesday, supervisors would no longer be allowed to donate the unspent money to charities or nongovernmental community organizations. They would also be barred from using the accounts to sponsor community events or take out advertisements associated with those events.

But the proposal doesn’t do away with spending entirely; supervisors would still be allowed to use their accounts to pay for approved capital projects in their districts, such as roads or libraries. Any unused funds would be transferred back to county coffers.

“People are concerned about this across the aisle,” Candland said. “We have to address the appearance of anything improper.”

The problem, he said, stems from the fact that the donations are often followed by some sort of public accolade — a thank you in event programs, names listed on donor roles — that could translate to personal or political gain.

Most of the donations don’t go above a few hundred dollars, but they can make a big difference in small-town politics, critics say. Given the relatively low turnout for county races — and the power of incumbency — the funds essentially ensure supervisors will have a campaign war chest to draw on throughout their tenure, some say.

When Supervisor Maureen S. Caddigan (R-Potomac) donated $1,000 this year to the Boys & Girls Club, she received a table at the organization’s “Steak ’n’ Stake” fundraising dinner. She spent another $300 from her account on a full-page ad in the program. The ad featured a large picture of her and said, “I listen — I care — I respond.” It also listed her district contact information.

Caddigan said that she thinks the political gain from such donations is minimal and that dipping into unspent office funds allows her to support worthy causes. She said that she is particularly passionate about the Boys & Girls Club and that her donations helped save the Dumfries area chapter from being shut down completely in 2009.

“I don’t think it bought me anything as far as elections are concerned,” Caddigan said. “The nonprofits are probably going to be hurt on this one.”

Supervisors have provided at least $489,000 in donations since 2004, according to a financial tally provided by county officials to The Washington Post.

There are a few restrictions on supervisors’ donations. State law prohibits donations to religious organizations, and all donations must be approved by the full board in a public meeting, county spokesman Jason Grant said.

Because unused money rolls over from year to year, the amounts a supervisor accumulates over time can be substantial. Combined, there is almost $1 million in the eight supervisors’ accounts. More than a third — $357,700 — is in the district account of W.S. Covington III (R-Brentsville) .

Late last year, he drew attention to the spending accounts after he proposed donating $100,000 to the Rainbow Therapeutic Riding Center, where his wife is the unpaid president of the board of directors, according to its latest public tax return. Covington withdrew the donation request after critics protested.

But the accounts remain a source of controversy. The extra money allows supervisors to run “a perpetual four-year campaign,” said Al Alborn, a conservative activist who has pushed against the program for years.

Martin E. Nohe (R-Coles) said there are times when the funds are vital to providing valuable services to the community. He pointed out how supervisors dipped into the accounts to help provide a more accessible home for a U.S. Marine who was paralyzed from the waist down while serving in Afghanistan. In that case, the donations were in the thousands and were small compared with the total cost of the project, which was spearheaded by other charities, but they made a difference, he said.

“It made that project possible and brought that Marine home,” Nohe said.

Many local charities said the funds are a valuable source of funding. When the food pantry at Action in Community Through Service ran out of money and food, for example, the supervisors’ donations were a big help, said Frances Harris, the executive director.

“It really made a huge impact, and it’s important for the community to know that [supervisors are] supportive, that they understand the need of the community,” Harris said.

She said individual supervisors have been recognized as “sponsors” of her group in the past but said they had not requested it.

That was not necessarily the case, however, when Covington gave $10,000 from his account to Gainesville Middle School last year, according to school officials. After Covington donated the money, his office called the school principal with one other detail, according to Alan Bisenieks, then the PTO president: A staffer asked if they could arrange for the supervisor to speak in front of a group. A night to honor rising sixth-graders was coming up, and Bisenieks said he arranged for Covington to speak at the event.

Covington confirmed that he spoke there and said he likes to speak to groups of parents and encourage them to get involved with the school — the subject of his talk that night.

He said he gets little, if any, political benefit.

“The more involved we are in our communities, the better we serve our community,” he said.