Blake Lively and Ryan Reynolds want a judge to gag Justin Baldoni‘s lawyer … claiming he’s making false statements about the case.

The megastars filed a letter in court Tuesday … and, in it, they ask the court to issue a protective order to stop Baldoni’s lawyers — led by Bryan Freedman — from engaging in “improper conduct” including going on an alleged “harassing and retaliatory media campaign” against Blake and Ryan.

They say he’s violating court rules that stop a lawyer from making statements to the press that are irrelevant to a case and might prejudice the jury.

In it, Blake and Ryan specifically mention the release of unedited footage from “It Ends With Us” filming … which Blake’s team claims “corroborates, to the letter, what Ms. Lively described” in her initial complaint back in December.

Remember, Lively accused Baldoni of sexual harassment and engaging in a coordinated effort to destroy her reputation. Baldoni has since filed his own $400 million lawsuit against Lively … accusing her of defamation, civil extortion and other allegations.

Baldoni’s team released the behind-the-scenes footage from the movie to prove he never made harassing comments … while Blake’s team pushed back and said Baldoni never discussed or choreographed the intimacy here — and, it made her uncomfortable.

Bryan Freedman’s been outspoken since taking Justin on as a client … including stopping by “TMZ Live” to discuss the case in a wide-ranging interview earlier this month all about smear campaigns in Hollywood.

Sources connected to JB tell TMZ … they believe it’s grossly unfair to impose a gag order after Justin has been defamed by the New York Times in an article that they say has cost him three jobs and hundreds of millions of dollars. All Justin wants to do, the source says, “is release videos and text messages to prove the allegations are false.”