Obama-era Attorney General Eric Holder accused Attorney General William Barr of being “nakedly partisan” and “unfit to be attorney general” in an op-ed published Wednesday night.

“I respect the office ad understand just how tough the job can be. But recently, Attorney General William P. Barr has made a series of public statements and taken actions that are so plainly ideological, that they demand a response from someone who held the same office,” Holder wrote in the Washington Post.

Holder then lashed out at Barr’s recent Federalist Society speech in which he railed against rising anti-police sentiment among “the left,” claiming it was “antithetical to the most basic tenets fo equality and justice.”

“It undermines the need for understanding between law enforcement and certain communities and flies in the face of everything the Justice Department stands for,” the former DOJ official added. “I and many other Justice veterans were hopeful that he would serve as a responsible steward of the department and a protector of the rule of law,”

“Virtually since the moment he took office, though, Barr’s words and actions have been fundamentally inconsistent with his duty to the Constitution. Which is why I now fear that his conduct — running political interference for an increasingly lawless president — will wreak lasting damage,” he concluded.

Holder was held in civil and criminal contempt of Congress in 2012 for failure to produce subpoenaed documents related to Operation Fast and Furious — a “gunwalking” operation that resulted in foreign nationals killing Border Patrol agent Brian Terry with a weapon sold knowingly through illegal straw purchases, ostensibly for ATF to track their use by Mexican drug cartels.

Holder’s op-ed comes after he claimed the Justice Department’s inspector general report showed “conclusively that there was a need for Russia inquiry” and accusing Barr of being “politically motivated.” The watchdog found the FBI committed 17 “significant inaccuracies and omissions” in its application to surveil former Trump campaign adviser Carter Page as part of its investigation into the 2016 Trump campaign.

“IG Report shows conclusively that there was a need for Russia inquiry. All those-including the AG-who questioned the motives of the career people at DOJ and FBI must acknowledge this. Do no more harm to these organizations. You were politically motivated; you’re now proven wrong,” Holder wrote on Twitter.

Barr’s statement on the report stands in stark contrast to Holder, saying the “FBI launched an intrusive investigation of a U.S. presidential campaign on the thinnest of suspicions that, in my view, were insufficient to justify the steps taken.”

“It is also clear that, from its inception, the evidence produced by the investigation was consistently exculpatory,” he added.