Justin Baldoni's PR Rep Files Suit Against Ex-Boss in Blake Lively Legal Drama

Justin Baldoni's PR rep Jennifer Abel is firing back at her former boss, Stephanie Jones, with her own lawsuit ... after being sued by SJ in December.

Abel has hired Baldoni's powerhouse lawyer Bryan Freedman, who accuses Stephanie of triggering the whole legal drama between Justin and Blake Lively involving their film, "It Ends with Us."

Freedman filed the counterclaims on Abel's behalf against Jones -- who's the CEO of the PR company Jonesworks, which still represents Justin.

In a statement, Freedman tells TMZ ... "It is undeniable that Stephanie Jones initiated this catastrophic sequence of events by violating the most basic of privacy rights, as well as any remaining trust her clients held."

Freedman says Stephanie is "no stranger to stirring up crisis scenarios for departing clients," accusing her of maliciously turning over "communications from the phone she wrongfully took from her own partner to her cohort Leslie Sloane, immediately after Jones was terminated for cause by Wayfarer due to her own wrongful behavior." Leslie, of course, is Blake's PR rep, who has also been sued by Baldoni.

Freedman goes on to say Lively "walked right into Ms. Jones’ ploy of bitter revenge against her most-trusted employee at the expense of her own long-term client."

The attorney ended with ... "We will not stop until our clients are cleared of all wrongdoing and compensated for the vast damages that they have incurred."

In the new court docs, filed Thursday, Abel responds to Jones' lawsuit against her, Baldoni, and Baldoni's PR crisis manager Melissa Nathan ... Abel makes a bunch of counterclaims, including invasion of privacy, false light and intentional infliction of emotional distress.

As you know ... Baldoni has filed a few major lawsuits in recent months -- including the massive $400 million lawsuit he and his production company, Wayfarer Studios, filed against Blake, Ryan Reynolds and Leslie Sloane.

In the suit, Baldoni claims the three started a smear campaign against him to take control of the movie "It Ends with Us."

Lively filed suit first against Baldoni in December, claiming he sexually harassed her on the movie set and later embarked on a targeted smear campaign against her in the media.

Kristin Tahler, partner at Quinn Emmanuel, who's representing Jones, tells TMZ ... “Ms. Jones’ lawsuit is based entirely on facts and concrete evidence. That suit clearly shows that Jen Abel conspired with Melissa Nathan and others to steal reams of confidential documents, clients and staff and eventually attempt to destroy the business that Ms. Jones spent decades building."

She continues, "Abel, Nathan, Baldoni and their co-defendants attempted to achieve these outcomes through bullying distortion and outright disparagement. These facts are backed up by dozens of messages provided in the suit we filed month ago and cannot be credibly disputed.