Attorneys for Robert F. McDonnell say that prosecutors pursuing a federal corruption case against the former Virginia governor overstepped when they moved to delay a related civil lawsuit, arguing that the action was intended to undercut McDonnell’s defense by keeping secret unflattering information about their star witness.

In a filing in federal district court in Richmond, the attorneys asked that a judge take steps to resume the civil case involving Jonnie R. Williams Sr., the Richmond businessman accused of lavishing McDonnell and his wife with gifts and money in exchange for their helping him and his struggling company, Star Scientific, a former small cigarette manufacturer that now sells dietary supplements.

The defense attorneys wrote that prosecutors’ efforts to delay the civil case — a lawsuit by shareholders claiming that Williams and Star Scientific misled them — seemed to be a tactic to limit the evidence to which McDonnell had access. The civil suit, they said, might unearth information that undermines Williams’s credibility and that would be vital to McDonnell’s defense.

“In short, the Government’s affirmative efforts to limit the flow of information to Mr. McDonnell violate his fundamental constitutional rights,” the attorneys wrote.

The filing is yet another indication of how vigorously McDonnell and his wife, Maureen, plan to fight the charges against them, even before their July 28 trial. Charged last month in a 14-count indictment, the McDonnells have pleaded not guilty, and their attorneys have filed several motions seeking materials and challenging various aspects of prosecutors’ case. Prosecutors and defense attorneys even litigated the extent to which the McDonnells can talk to their family and friends as the case proceeds.

Prosecutors had requested — and a judge granted — a delay in the civil case last month. Such an action is common in instances where civil and criminal cases overlap, although defense attorneys noted that McDonnell was in the unusual position of not being a litigant in the civil case, and because the criminal case is public, there was no need to stop the civil case to keep secret a criminal probe by a grand jury.

In asking to intervene in the civil case, prosecutors wrote that letting it go forward might give the McDonnells material “that would not be available to the criminal defendants within the confines of the criminal discovery process.” They asked a judge to put on hold the process for uncovering and sharing evidence between the parties in that case.

McDonnell’s attorneys wrote that argument was “not legitimate” and that prosecutors seemed to be trying to stop any investigation of Williams or Star Scientific so that no information came to light that could be damaging to their criminal case. They asked a judge to rule that stopping the civil case was an effort to impede their own ability to collect evidence, akin to prosecutors persuading witnesses not to talk to defense lawyers.

“Concluding otherwise would substantially expand the Government’s power to unilaterally decide what evidence the defense, the judge, and the jury get to hear,” the defense attorneys wrote.

As of Friday afternoon, prosecutors had yet to respond to defense attorneys’ motion and a judge had yet to rule. Williams stepped down as Star Scientific’s chief executive last year, and the company has indicated that it is contemplating changing its name to Rock Creek Pharmaceuticals.