Washington, Oct 19 (AFP) Hillary Clinton warned that Russia is grooming a US Democratic candidate for a third-party run next year, prompting the accused Tulsi Gabbard to unleash an all-out attack Friday on the "queen of warmongers" ex-secretary of state.

Clinton -- and history from her 2016 presidential defeat to Donald Trump -- suggested that the result of the Russian-backed move would be to divide the US electorate and help Trump win again in 2020.

"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 said on the "Campaign HQ" podcast that first aired Thursday.

"She's the favorite of the Russians. They have a bunch of sites and bots and other ways of supporting her so far." Clinton did not name Gabbard, but the Hawaii congresswoman essentially acknowledged she was the target by blasting out a stunning Twitter thread against the former first lady.

"Great! Thank you @HillaryClinton. 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," Gabbard ranted at her fellow Democrat.

Gabbard, 38, accused 71-year-old Clinton, long a doyenne of the Washington establishment, of leading a "concerted campaign" to destroy her reputation.

"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," she added. "It's now clear that this primary is between you and me," she sneered. "Don't cowardly hide behind your proxies. Join the race directly." Clinton has said she is done running for president.

Gabbard's campaign is hanging by a thread. She is polling at barely one percent support in a sprawling field that includes former vice president Joe Biden and senators Elizabeth Warren and Bernie Sanders.

Her tirade is startling given that it is from one presidential candidate to her own party's 2016 nominee, herself the target of Russian interference that year.

US media analysis has shown that sites tied to Russia have celebrated Gabbard's campaign launch, defended her controversial 2017 meeting with Syrian President Bashar al-Assad, and attacked people who have suggested Gabbard is a pawn for Moscow.

Last week The New York Times quoted influential Republicans who said they were impressed with her. Far-right conspiracy theorist Mike Cernovich said she "seems very Trumpian."

Gabbard has rejected some of the support from rightwing or white nationalist sources, and during last week's Democratic debate she chastised the Times for publishing "smears" and said television commentators were "completely despicable" for calling her a Russian asset.

The US intelligence community has concluded that Russia interfered in the 2016 election to help boost Trump's chances of victory.

Clinton said it was clear Russia is laying the groundwork for similar interference in 2020.

In 2016, Green Party liberal Jill Stein won more votes than Trump's victory margin in Michigan, Pennsylvania and Wisconsin, states that could have secured the presidency for Clinton. (AFP)

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