Uber's ex-CEO Travis Kalanick is under fire, but he's hardly out of supporters.

Kalanick, who resigned in June under pressure, got sued earlier this month by Benchmark Capital. Benchmark, a VC firm that is a major investor in Uber, accused Kalanick of "gross mismanagement and misconduct" and withholding material information. Lawyers for Benchmark are seeking to block Kalanick from filling the two vacant board seats he still controls.

Uber investors are far from united in that view, however. That became clearer than ever yesterday, when another major Uber investor, Shervin Pishevar of Sherpa Capital, sent a letter to the Uber board of directors that was sharply critical of Benchmark's move. The letter was reported by Reuters and published in full by TechCrunch

Pishevar isn't just venting to the board—he has also filed a motion to intervene (PDF) in the court case against Kalanick, and he accuses Benchmark of using "dirty tactics and strong arming" to push out the former CEO. The motion points out that Benchmark's $27 million investment in Uber has ballooned to be worth $8.4 billion, but "greedily, Benchmark wanted more." Pishevar's lawyers continue the narrative:

Without notice to the Board, in June of this year, just days after Kalanick’s mother was killed in a tragic boating accident, which also critically injured his father, Benchmark capitalized on grieving Kalanick’s vulnerability by ambushing him alone at a hotel room in Chicago and demanding that he resign as CEO and agree to restrictions on his Board seats. Benchmark threatened that if he did not, Benchmark (and other investors whom Benchmark enlisted in its efforts) would begin a public campaign against him, the obvious effect of which would be not only to smear his reputation, but to harm the Company that he founded and built.

"If Benchmark insists on trying to use the courts to try to take over this company, we are committed to doing everything we can to try to stop this abuse,” Pishevar wrote in his letter to the board.

He also accused Benchmark of violating its fiduciary duty, because it would "talk to others inappropriately." Pishevar said he has "tried in every way possible to convince my friends at Benchmark to drop this lawsuit, to end their public campaign against the founder and the company, and to divest their shares under a proposal which would reward them hugely for their investment."

Pishevar's motion to intervene was filed yesterday in Delaware's Chancery Court, where the Benchmark case is being litigated.