Five former Virginia attorneys general want the federal corruption charges against Robert F. McDonnell thrown out, arguing in a filing Wednesday that there is nothing illegal about what the former governor is accused of doing for a wealthy Richmond businessman.

The filing largely echoes McDonnell’s motion to dismiss the case, which argues that nothing he did for businessman Jonnie R. Williams Sr. constitutes an “official” act.

To substantiate the corruption charges, prosecutors must prove that the governor and his wife took “official acts” to help Williams and Star Scientific, a struggling dietary supplement company Williams used to run, in exchange for loans and gifts that they say Williams lavished on the couple.

But the filing by the former attorneys general, first reported by the Richmond Times Dispatch, goes further, asserting that if federal prosecutors’ “expansive interpretation” of the corruption charges is adopted into law, it could “wreak havoc upon the public life of Virginia.” Future governors, the filing says, might be reluctant to invite state business leaders on foreign trade missions or to host campaign donors at the governor’s mansion, things that are now routine.

“Future Attorneys General will be well-advised to caution their Governors (and other elected officials) not to meet with campaign contributors unless they can affirmatively demonstrate that they are granting equal access to those who gave no contribution or who contributed to the other side,” the filing says. “Such a regimen would be very difficult to administer and would inevitably result in an overall decrease in meetings between public officials and private citizens, a decidedly unhealthy development.”

The filing — which seeks to allow the attorneys general to file a brief in support of the McDonnells’s motion to dismiss — is likely to have little immediate impact on the legal case, if any at all. Earlier this week, U.S. District Judge James R. Spencer rejected a similar request by the National Association of Criminal Defense Lawyers to file a brief.

But the filing, like many others before it, could subtly educate Spencer and the public on defense attorneys’ view of the case.

It also demonstrates that McDonnell and his wife, Maureen, still enjoy broad, bipartisan public support.

Written by lawyers William H. Hurd and Stephen C. Piepgrass of the Troutman Sanders firm, the brief was signed by Andrew P. Miller, J. Marshall Coleman, Mary Sue Terry, Stephen D. Rosenthal and Mark L. Earley — Republican and Democratic attorneys general spanning three decades in office.

Terry, a Democrat who served as attorney general from 1986 to 1993, said she received a copy of the filing from Hurd and was moved to sign it because of how the case could “change the democratic process in Virginia.”

“I’m just saying that the McDonnell case is filled with salacious facts, and I hope they don’t lead to bad law,” Terry said.

Prosecutors have alleged that Williams showered the governor and his wife with loans and gifts, including golf outings and expensive clothing. In exchange, they allege, the couple hosted a product launch for Star’s dietary supplement, Anatabloc; promoted the supplement at public events; arranged meetings between Williams and senior state health officials; and encouraged state researchers to consider conducting trials of the product.

The McDonnells have pleaded not guilty to the charges, and a jury trial is scheduled for July 28. A Justice Department spokesman declined to comment on the filings.

Also on Wednesday, prosecutors responded for the first time to the McDonnells’s request to be tried separately, asking a judge not to consider details of the couple’s testimony behind closed doors without giving the government access.

Those details are contained in sworn declarations from the McDonnells’s defense attorneys, who want to present them to the judge — but not to prosecutors — as part of their bid to separate the cases.

Defense attorneys have argued that if the cases were separated, Maureen McDonnell would likely agree to testify — without fear of incriminating herself — that her husband was largely unaware of her dealings with Williams.

And if the cases were separated, they have argued, the former governor would be able to testify on his own behalf without his wife silencing him through marital privilege.

Prosecutors wrote Wednesday, though, that they could not respond fully to the request to sever the cases without knowing more precisely what the pair might say.

As of Thursday afternoon, a judge had yet to rule on any of the filings.

Rosalind S. Helderman contributed to this report.