Lawyers for 93-year-old Sumner Redstone are saying his mental status is sound and not in dispute and that he therefore does not need an examination to determine his capacity, as demanded by his long-time-confidant-turned-frenemy, Viacom CEO Philippe Dauman. The attorneys filed papers in late June rejecting a demand that the billionaire media baron make himself available for a full psychiatric examination in his Beverly Park home as soon as Aug. 17.

Just as vehemently, Dauman’s lawyers on Wednesday renewed their demand that the exam occur as soon as possible. They said the need for the review has been made clear by the starkly divergent opinions earlier experts previously have reached about the mental capabilities of Redstone, the Harvard-trained lawyer who is now a frail, bed-ridden shell of his former self.

“In light of Mr. Redstone’s precarious health and mental state, time is of the essence,” said a filing Wednesday by Dauman. “It is obvious that this matter can only be fairly adjudicated if there is an immediate examination of Mr. Redstone by Plaintiff’s order a psychiatric examination of the frail executive, who controls ownership of both Viacom and CBS Corp.”

The motion was made by lawyers for both Dauman and George Abrams, a previous long-time confidant of Redstone’s who was also ejected from the board that oversees the billionaire’s stake in Viacom and CBS Corp. The two men told Massachusetts probate court Judge George F. Phelan that they want a professor of psychiatry and a professor of neurology — Spencer Eth and Bruce Price — to visit Redstone’s Beverly Park mansion to complete their examinations. The two plaintiffs also called for an order allowing Redstone’s staff and medical assistants to attend the exams, along with a speech pathologist, Anne Lefton, who has become Redstone’s regular in-house interpreter.

Lawyers for the frail magnate, who eats through a feeding tube, made it clear in their filing Wednesday that they oppose the exam by Eth and Price. They said the magnate’s condition has stabilized since last year, when he had to be hospitalized and was described by visitors as vacant, almost ghostly.

Many visitors and family members agreed that Redstone’s condition had spiraled downward after two long-time lady companions, Sydney Holland and Manuela Herzer, were thrown out of his Beverly Park mansion. Redstone first ejected Holland, 44, when he learned the some-time dating service owner was cheating on him with a younger man. Herzer was next out the door, in October, when Redstone accused her of cutting off his access to yet another girlfriend, who regularly came to his home to provide sex therapy.

Dauman and Abrams, who served as Redstone’s lawyer for more than half a century, filed their lawsuit in the Boston-area probate court after being summarily pushed out of Redstone’s life in May. The two men previously had been among Redstone’s closest advisers but he accused them of being disloyal and not adhering to his wishes about his media empire. Both were thrown off the board and the trust that oversee National Amusements Inc. (NAI), the theater chain that also serves as the holding company for Redstone’s shares in Viacom and CBS Corp.

Dauman and Abrams have asked Phelan to order that they be restored to both the NAI board and trust. Viacom controls BET, VH1, Nickelodeon and Paramount Pictures, while CBS Corp. controls the television network and Simon & Schuster. The trust will wield tremendous power once Redstone dies or is declared incapacitated; having the power to determine the fate of the shares Redstone uses to control the two corporations. Their total book value stands at more than $40 billion.

The bad news came to Dauman and Abrams in mid-May, in the form of a FAX from an obscure lawyer not previously connected to Redstone. The formal letters from Michael Tu told the two men they were no longer needed on the NAI board or the Sumner M. Redstone Trust. Both men questioned whether their long-time friend was really behind the ouster. In alternative, they theorized it was Redstone’s daughter, Shari, who engineered the maneuver as part of her plot to become the secret hand guiding Viacom. Over many years, she had made no secret of her displeasure with the conglomerate’s underperformance and she pinned much of the responsibility on its CEO, Dauman. The 62-year-old heiress sharply denies the contention that she made her father push Dauman and Abrams out, noting that she voluntarily passed up an opportunity, earlier this year, to become chair of Viacom and of CBS Corp.

It is unclear when Judge Phelan will rule on the motion demanding a mental exam. The judge previously set out a protracted briefing schedule for case — focusing on issues like the mental exam and the question of which state’s courts should oversee Redstone’s case. California is also in the picture because National Amusements and Shari Redstone went to a Los Angeles judge, seeking to have the ouster of Dauman and Abrams from the NAI panels reversed.  But that judge, David J. Cowan, appears so far to be waiting for the Massachusetts case to run its course.

Also in the mix: Delaware’s Chancery Court, which oversees governance in the state that is the corporate home of most American companies. A judge there will rule on a case in which the five Viacom directors challenged their replacement on the conglomerate’s governing board.