A judge rejected Flanagan's attempts Thursday to get the case reduced or the charge dismissed.
Flanagan has repeatedly argued that the singer is being treated more harshly than other people who have been caught driving without a valid California license. He said under normal circumstances, Spears should be allowed to pay a $10 fine and not face criminal prosecution.
He said Thursday that Los Angeles Superior Court Judge James A. Steele cited Spears' celebrity status during an in-chambers meeting as a reason for not reducing the case to an infraction.
"He says, 'But I've never done that before. I'd hate to do it the first time and do it for Britney Spears because then it would appear like she's getting special treatment,"' Flanagan recounted Steele telling him.
Steele said through a clerk that he could not comment on the conference in his chambers. A court reporter was not present for the meeting. Flanagan said he will appeal a previous ruling by the judge denying Spears' motion to dismiss the case.
If the case begins as scheduled on Oct. 15, Flanagan said he doesn't plan to present any witnesses or do anything more than make opening and closing arguments to jurors.
"I'm just going to sit there," he said. If Spears is convicted, he said he will appeal that judgment.
The charge is the last remnants of a criminal case city prosecutors lodged against Spears after she hit a parked car in August 2007 and left without notifying the owner. She was originally also charged with hit-and-run, but Spears settled that charge through an agreement with the other car's owner.
Steele is not the only one Flanagan accused of treating Spears, 26, unfairly. On Thursday he said Michael Amerian, a city prosecutor handling the case, is trying to use the matter to boost his own profile because he running to become City Attorney.
"I am right on this issue and I'm not going to bow down to this guy because he's running for City Attorney," Flanagan said.
Amerian vehemently denied Flanagan's contention.
"We're treating her fairly in light of the facts in this case," Amerian said. He said he has never mentioned his bid for elected office when discussing Spears' case. He said prosecutors have been consistent on how they've handled the case since it was filed last summer.
"We're trying to treat her as we have anyone else who's been charged with a hit-and-run as well as driving without a valid license," Amerian said.
Flanagan said prosecutors have gone to unusual lengths to try to keep the case alive, including citing Spears' divorce from ex-husband Kevin Federline. Flanagan said prosecutors noted that when Spears filed for divorce in November 2007, she had to certify she had been a California resident for at least six months.
The criminal case was filed in August 2007.
Drivers are supposed to get a California license within 10 days of establishing residency in the state. But Flanagan said Spears had a valid license in Louisiana, which is one of several states where the singer has homes.
The case has been repeatedly postponed since Spears was placed under the conservatorship of her father, James, in February. That arrangement means that he controls the singer's personal and financial affairs and was a result of several high-profile incidents of erratic behavior, including two hospitalizations.