Attorneys for former Virginia governor Robert F. McDonnell asked a federal judge on Tuesday night to drop the corruption charges against their client, arguing that McDonnell never used or promised to use any actual government power in exchange for gifts and loans from a wealthy Richmond businessman.

Shortly before midnight, a filing was entered in which McDonnell asked that he and his wife be tried separately so each could talk about the other at trial.

Robert McDonnell’s attorneys wrote in the filing that Maureen McDonnell was the “essential link” in the case against her husband, and if she herself were not on trial, she would “testify that her relationship with Mr. McDonnell was strained for a number of reasons, including Mr. McDonnell’s demanding work and travel schedule, and that, far from acting in concert, they had no such agreement and he had no timely knowledge of many of her interactions with [Richmond businessman Jonnie R.] Williams.” If she were on trial, though, she would invoke her Fifth Amendment right not to testify, the attorneys wrote.

The attorneys also wrote that Robert McDonnell would be limited in testifying on his own behalf at a joint trial because his wife would invoke marital privilege and prevent him from detailing their conversations.

Repeating many of the claims they have made in previous filings, McDonnell’s attorneys argued in their long-awaited motion to dismiss that what prosecutors allege McDonnell did for Williams — including arranging meetings between Williams and state officials and promoting Williams and his company — did not constitute promising to perform or actually performing “official acts.” And because the Republican former governor did not promise or perform “official acts,” they wrote, he cannot be charged with any corruption counts.

“Public officials perform ‘official acts’ only when they exercise actual governmental power or improperly lobby other officials to exercise such power,” the attorneys argued. “Returning a supporter’s phone call, asking a subordinate to meet with a supporter, attending a supporter’s event, inviting a supporter to a reception, or saying nice things about a supporter are not ‘official acts’ — even if they enhance that supporter’s actual or perceived stature — because none of those actions deploy the sovereign power of government.”

McDonnell and his wife, Maureen, were charged in January in a 14-count indictment that alleges they broadly lent the prestige of the governor’s office to Williams and the struggling dietary-supplement company he used to run, Star Scientific, in exchange for gifts and loans totaling at least $165,000.

Prosecutors allege that the couple hosted a product launch for Star’s dietary supplement, Anatabloc; promoted it at public events; arranged meetings between Williams and senior state health officials; and encouraged state researchers to consider conducting trials of the product.

McDonnell and his wife also were charged with making false statements on financial documents, and Maureen McDonnell was charged with obstructing the grand jury’s investigation. Their attorneys did not move to dismiss those counts, though they have pleaded not guilty to all the charges. A jury trial is scheduled for July 28.

Experts had long speculated — and the McDonnells’ attorneys had previewed in other filings — that the notion of “official actions” would be key to the couple’s defense. Defense attorneys had even sought to force prosecutors to be more specific about those actions, although a judge rejected that bid earlier this month.

To prove the corruption charges, the law requires that prosecutors show that McDonnell and his wife performed — or at least promised to perform — official actions for Williams. But left unsettled is what constitutes an official action.

In Tuesday’s filing, defense attorneys made the case that none of what McDonnell did or promised to do fit the bill. Even when he arranged meetings between Williams and state officials, they argued, he made no attempts to influence the outcomes of those meetings.

Defense attorneys also argued that federal prosecutors were trampling Virginia law — which they said explicitly legalized McDonnell’s unlimited acceptance of gifts — and should their prosecution be successful, they would effectively criminalize even routine interactions between politicians and donors.

“If the Government were correct that every meeting referral for a donor, statement to third parties supporting a benefactor, or party invitation for a supporter and a supporter’s associates constitutes federal bribery, then countless current and routine political practices are now felonies,” the attorneys wrote.

Early in their memo accompanying the motion to dismiss, the attorneys highlighted a political action committee’s recent offer to give donors access to a private dinner with Gov. Terry McAuliffe (D), McDonnell’s successor.

“Neither that solicitation nor Mr. McDonnell’s alleged conduct violate federal criminal law,” the attorneys wrote.

Prosecutors have argued that McDonnell did take official actions for Williams, though they needed to prove only that such actions were promised and that the former governor acted for his benefactor on an “as needed” basis. They have until April 24 to respond to the motion to dismiss, and a hearing is tentatively scheduled on the matter for May 19.

Also Tuesday, McDonnell’s attorneys filed a motion asking for specific procedures to handle prospective jurors because of intense news media coverage of the case and another motion asking to remove from the indictment details about Maureen McDonnell’s buying and selling of Star Scientific’s stock.

Prosecutors have alleged the buying and selling of stock was meant to help Maureen McDonnell avoid disclosure requirements; defense attorneys argued that the stock transactions and the non-disclosure were not themselves illegal, and the stocks were not bribes from Williams or Star.