The Prince William Board of County Supervisors extended the deadline for residents to pay their property taxes Tuesday because of the impact of the federal government’s shutdown.

Residents can now pay their property taxes, generally assessed on vehicles, by Nov. 21 without penalty. More than 75 percent of county residents have already paid their car taxes, officials said, and they will not receive a refund.

The board’s 6-to-1 vote came over the objections of county staff members and Chairman Corey A. Stewart (R-At Large), who said Prince William could endanger its AAA bond rating, a measure of fiscal strength that allows the county to borrow millions at lower interest rates. Stewart was the only member to vote against the measure; Supervisor John D. Jenkins (D-Neabsco) was absent.

Supervisor W.S. Covington III (R-Brentsville) had offered the emergency measure, which was passed without the usual waiting period and study required by board rules, because of calls he had received from residents worrying about paying the tax. The tax was due Monday; supervisors had 24 hours under state law to pass an extension.

“We need to show a little bit of compassion to our taxpayers,” Covington said.

Deputy County Executive Christopher Martino said Prince William finance officials “very strongly” opposed the move, saying that although the delay does not necessarily hurt the county financially, it could serve as a precedent for Wall Street agencies to downgrade Prince William.

“The board has made a very irresponsible decision,” Stewart said. “I think the board just copied what the federal government [says]: ‘You can get the goodies without having to pay for it.’ ”

Covington and others said they doubted the move would affect the county’s position with Wall Street rating agencies. Regardless, he said the board made the right move.

“It sends a clear statement that democracy lives on and we’re not controlled by Wall Street,” Covington said. “If the bond [agencies] can dominate democracy, then something is seriously wrong with this country. It was the right decision and the right place to go.”