Gabbard claims to have suffered “actual damages” of at least $50 million because of Clinton’s charge, though the lawsuit does not name a specific dollar amount sought from Clinton.

The comments in question came last fall when Clinton appeared on a podcast hosted by former President Barack Obama’s 2008 campaign manager, David Plouffe. The two discussed the upcoming presidential election, prompting Clinton to muse that President Donald Trump and the GOP are "grooming" a potential spoiler candidate for a third-party bid.

“I’m not making any predictions, but I think they’ve got their eye on somebody who’s currently in the Democratic primary and they’re grooming her to be the third-party candidate,” Clinton told Plouffe.

She continued of the unnamed candidate: “She’s the favorite of the Russians. They have a bunch of sites and bots and other ways of supporting her so far and that’s assuming Jill Stein will give it up because she’s also a Russian asset.”

While Clinton did not mention Gabbard, a spokesperson confirmed the “Russian asset” comment referred to the Hawaii congresswoman. Both Senate investigators probing Russian interference in the 2016 election and former special counsel Robert Mueller found that Russian agents sought to boost Green Party candidate Jill Stein that year to siphon votes away from Clinton.

The comments were quickly condemned by some of Gabbard's rivals in the race, and Stein. And Gabbard, who has shot down suggestions she might run as a third-party candidate should she not earn the Democratic nomination, fired back with a searing response on Twitter.

"Thank you @HillaryClinton," Gabbard wrote. "You, the queen of warmongers, embodiment of corruption, and personification of the rot that has sickened the Democratic Party for so long, have finally come out from behind the curtain. From the day I announced my candidacy, there has been a concerted campaign to destroy my reputation. We wondered who was behind it and why. Now we know — it was always you, through your proxies and powerful allies in the corporate media and war machine, afraid of the threat I pose."

The four-term congresswoman is often mentioned in Russian propaganda and media, including by Kremlin-backed news agency RT, and Gabbard has faced criticism for foreign policy views that some allege are closely aligned with Russia and other foreign adversaries of the United States — especially her views on Syria and Syrian President Bashar Assad.

Though Gabbard has gained fans among liberal activists and even some Republicans, the congresswoman has missed the past two Democratic debates and has struggled in polling and fundraising.

Gabbard has proven a thorn in the side of the Democratic establishment, saying in a debate last year that the party whose nomination she seeks is “not the party that is of, by and for the people” while lobbing brutal attacks against her rivals on stage.

The lawsuit, which names Gabbard's presidential campaign committee as a co-plantiff, offers a scathing rebuke of Clinton while portraying Gabbard as a public servant devoted to putting country before party.

Describing her 2016 endorsement of Sanders, the lawsuit says Gabbard, then a vice chair for the DNC, backed the Vermont senator despite knowing that “Clinton had a stranglehold over the Democratic party and that crossing Clinton (who considered herself the ‘inevitable nominee’) could mean the end of her own political career.”

The move, according to the suit, made Clinton "extremely angry — to put it mildly" and prompted a flurry of menacing emails from Clinton's aides. Describing Clinton as “a cutthroat politician by any account,” the suit alleges she advanced the “conspiracy theory” to derail Gabbard’s presidential campaign as payback.

A spokesperson for Clinton did not immediately return a request for comment.

The former secretary’s brush up with Gabbard is the second time in as many days Clinton has been in the news for contentious remarks directed at her own party.

On Monday, Clinton came under fire for her candid assessment of Sanders in an upcoming documentary about her 2016 run. In an interview with The Hollywood Reporter, she doubled down on her assertion that “nobody likes” Sanders and that his claims of being an outsider candidate are “baloney,” drawing pushback from fellow Democrats concerned at maintaining party unity.