A simple favor.

Blake Lively’s lead attorney, Mike Gottlieb, allegedly threatened to release Taylor Swift’s private text messages if the singer didn’t publicly support the star in her “It Ends With Us” legal battle.

Justin Baldoni’s legal team laid bare the bombshell allegations in a shocking new court filing obtained by The Post; however, Gottlieb shot down the accusations, calling them “categorically false.”

Taylor Swift and Blake Lively at the Super Bowl LVIII. Getty Images

Last week, Swift was dragged into Lively’s ongoing feud with Baldoni when the superstar singer in the legal war.

In a letter to the judge on Wednesday, Baldoni’s lawyers explained why they want to talk to Swift, particularly, after Lively and her husband, Ryan Reynolds, attempted to quash the subpoena.

“The Lively Defendants’ insistence that the Subpoena seeks irrelevant information is wrong,” Bryan Freedman, Baldoni’s attorney, wrote in the latest legal doc.

Freedman also claimed that he received a tip from an anonymous source who alleged that Lively “requested that Taylor Swift delete their text messages,” per the filing.

Freedman argued that the source “is highly likely to have reliable information,” which he believes could help the case.

Blake Lively and Ryan Reynolds. Christopher Peterson / SplashNews.com

Taylor Swift at a Kansas City Chiefs game. Getty Images

Taylor Swift is the godmother to Blake Lively and Ryan Reynolds’ three daughters. GC Images

In the legal letter, Freedman also claimed that Lively’s lawyer allegedly contacted an attorney at Venable, the firm that represents the “Bad Blood” singer, “and demanded that Ms. Swift release a statement of support for Ms. Lively,” while also “intimating that if Ms. Swift refused to do so, private text messages of a personal nature in Ms. Lively’s possession would be released.”

According to Freedman, via the filing, he was told that one of Swift’s representatives “addressed these inappropriate and apparently extortionate threats” in at least one written communication with Gottlieb.

“It is those communications that the Wayfarer Parties seek to obtain,” the letter stated, adding that alleged communication could be possible evidence of “an attempt to intimidate and coerce a percipient witness in this litigation.”

Lively’s attorney denies the accusations. Getty Images

But Lively’s attorney denied Freedman’s allegations in a statement to The Post.

“This is categorically false. We unequivocally deny all of these so-called allegations, which are cowardly sourced to supposed anonymous sources, and completely untethered from reality,” Gottlieb said.

“This is what we have come to expect from the Wayfarer parties’ lawyers, who appear to love nothing more than shooting first, without any evidence, and with no care for the people they are harming in the process. We will imminently file motions with the court to hold these attorneys accountable for their misconduct here.”

Blake Lively called Taylor Swift and Ryan Reynolds “my dragons” in an alleged text message to Justin Baldoni. GC Images

Blake Lively sued her “It Ends With Us” co-star for alleged sexual harassment. GC Images

Lively’s legal team filed a motion to strike Freedman’s letter on Wednesday afternoon, claiming the filing’s sole purpose was to “launder scandalous and defamatory allegations about Ms. Lively and opposing counsel into the press.”

“That letter, which was not filed with any evidentiary support of any kind, much less anything under oath, falsely accuses Ms. Lively, and her counsel, of engaging in ‘witness tampering and evidence spoliation’ based on an undisclosed anonymous source,” one of the actress’ lawyers, Esra A. Hudson, fired off in the request obtained by The Post.

“It should be unnecessary to respond to anonymously sourced, baseless, allegations recklessly leveled without any supporting evidence. It is worth stating for the record, however, that each of the

allegations in the Freedman Letter is unequivocally and demonstrably false,” the filing read.

Blake Lively’s attorneys quickly filed a motion to strike the letter. ©Sony Pictures/Courtesy Everett Collection

“It does not seek any form of relief, is irrelevant to any motion currently pending before the Court, and serves no legitimate purpose. It is not useful to the Court in any respect.”

The Post reached out Freedman and Swift’s rep for comment but did not immediately hear back.

Swift, who is the godmother of Lively and Reynolds’ three daughters, was brought up several times in Baldoni’s countersuit, in which he claimed the international pop diva and Reynolds were presenbetween him and Lively that took place at the couple’s New York penthouse.

In his countersuit, Baldoni also claimed that Lively called herself Khaleesi from “Game of Thrones” and referred to Reynolds and Swift as “my dragons” in an alleged text exchange.

Justin Baldoni and Blake Lively on the set of “It Ends With Us.” Christopher Peterson / SplashNews.com

He countersued her and Ryan Reynolds for $400 million. GC Images

The Grammy winner’s team shortly after the news of her subpoena made headlines.

“Taylor Swift never set foot on the set of this movie, she was not involved in any casting or creative decisions, she did not score the film, she never saw an edit or made any notes on the film, she did not even see ‘It Ends With Us’ until weeks after its public release, and was traveling around the globe during 2023 and 2024 headlining the biggest tour in history,” a Swift representative told The Post.

Their trial is set for March. Kristin Callahan/Shutterstock

Lively kicked off the legal war whenclaiming he sexually harassed her on the set of “It Ends With Us.”

Baldoni, who served as director and the love interest of Lively’s character in the film, countersued the actress and her husband fo, accusing the couple of defamation, civil extortion, false light invasion of privacy, and more.

Each party has denied the other’s allegations.

Lively and Baldoni’s trial is set for March 2026.