Hillary Clinton has shrugged off Donald Trump’s charge that she’s a serial liar — but that’s precisely how she was described by a liberal Democratic activist to her campaign chair, John Podesta.

“Hillary should stop attacking Bernie [Sanders], especially when she says things that are untrue, which candidly she often does,” Brent Budowsky, a former aide to late Texas Sen. Lloyd Bentsen, wrote in a March 13, 2016, email to Podesta.

The activist also feared that Clinton would have a hard time beating Republicans — except for Trump.

“Right now I am petrified that Hillary is almost totally dependent on Republicans nominating Trump,” said Budowsky.

“She has huge endemic political weaknesses that she would be wise to rectify . . . even a clown like Ted Cruz would be an even money bet to beat and this scares the hell out of me.”

Budowsky instead suggested Clinton “look for issues where she can dovetail with Bernie.”

That advice appears to have been taken — Clinton has adopted policies similar to her former rival’s on college affordability and the minimum wage.

In an earlier email, also to Podesta, Budowsky warned that “people close to the Clintons” are telling reporters that Bill Clinton’s sex life will hurt his wife’s campaign.

“I had a multi-email exchange with someone in the media this morning — a name you would know — who is telling me there are people close to the Clintons who say WJC’s sex life could be damaging to her. I responded that I totally disagree with that,” Budowsky wrote on Jan. 10, 2016.

“Whoever is peddling this crap from somewhere within the Clinton camp is having the effect of encouraging the media to give the issue more prominence.

“They are hurting both Clintons. I always stay out of intra-staff stuff like this, both Clinton’s would be well advised to advise the people in their orbit to shut the hell up about this,” he concluded.

Although Podesta received advice from Budowsky for years, he didn’t hold him in high esteem.

“To you only: Brent Budowsky. Leftie with no following . . .,” Podesta wrote Clinton aide Cheryl Mills on Jan. 8, 2014.