Blake Lively allegedly used the possibility of revealing Taylor Swift’s private messages as leverage to get her to support her in a dispute with Justin Baldoni.

Blake Lively allegedly threatened to leak embarrassing private texts from bestie Taylor Swift unless the pop star agreed to publicly back the actress in her feud with co-star Justin Baldoni, DailyMail.com can exclusively reveal.

The explosive revelation appears in a legal letter addressed to a judge by Baldoni’s lawyers on Wednesday, in response to Lively’s request to quash their subpoena to the singer.

The court filing also alleges that the Gossip Girl alum had urged Swift, 35, to delete the text messages between them during her escalating legal battle with Baldoni, 41.

The latest twist sheds further light on the collapse of Lively and Swift’s once-close friendship – which has gone cold amid the actress’s high-stakes lawsuit involving the actor.

Since then, both Swift and Lively have been subpoenaed for communications about the case, despite the superstar’s attempts to distance herself from the furor.

In the court letter obtained by DailyMail.com, Baldoni’s lawyers hit back at Lively’s ‘wrong’ claims that their proposed subpoena to Swift ‘seeks irrelevant documents’.

They maintained that the order is aimed at obtaining information related to ‘witness tampering and evidence spoliation, specifically that Lively had attempted ‘coerce’ Swift into publicly siding with her. 

Specifically, the letter notes that Baldoni’s team received information that Lively had contacted Swift’s lawyers and ‘i) demanded that Ms. Swift release a statement of support for Lively, and ii) intimated that, if Ms. Swift refused to do so, private text messages in Lively’s possession would be released.’

The letter states that his lawyers are ‘further informed and believe that Ms. Lively requested that Ms. Swift delete their text messages’ – which, according to insiders, may have contained details from over a decade of friendship, relationships, and private confidences.

According to Baldoni’s lawyers, Swift’s attorneys purportedly addressed Lively’s ‘inappropriate and apparently extortionate threats’ in at least one written communication sent to her legal team.

‘It is those communications that the Wayfarer Parties seek to obtain by way of subpoena, as they would evidence an attempt to intimidate and coerce a percipient witness in this litigation’, the document states. 

Swift, whose hit song ‘My Tears Ricochet’ was featured in the soundtrack of It Ends With Us, was pulled into the rollercoaster saga earlier this year when Baldoni filed a $400million countersuit accusing Lively and her husband Ryan Reynolds of defamation. 

Explosives text messages from Baldoni’s complaint revealed Lively had referred to the superstar singer and her husband, as ‘my dragons’ in a bid to intimidate him over ill-fated flick It Ends With Us.

Since then, Swift, 35, has reportedly been trying to distance herself from the dramatic legal drama and her friendship with Lively. 

Those efforts have included icing Lively out of her inner circle while boyfriend Travis Kelce has unfollowed Reynolds on Instagram.

The new revelation marks yet another bombshell twist in a case that has dragged in multiple A-listers and resulted in some legal zingers – among them Lively’s dragon claim.

The mom-of-four has also been accused of failing to read the novel on which the movie is based until well after filming started and forcing Baldoni and his family to sit in the basement during the premiere due to her refusal to be in the same room as him.

On top of that, some of her allegations have begun to look dubious such as the claim that Baldoni had nuzzled her neck and told her ‘you smell so good’ during a dancing scene.

Although the mom-of-four claimed it had been filmed with microphones off, DailyMail.com obtained raw footage that showed the sound was on and that the conversation had instead been about the scent of Lively’s fake tan.

Attention has now turned to who else could be subpoenaed in the case, with Reynolds odds-on to have his communications scrutinized by Baldoni’s team.

Last week, speculation arose around Swift and Reynolds’ friend Hugh Jackman with reports saying that they too are facing a legal grilling.

Swift is reportedly furious over being dragged into the case and has not been photographed with Lively for months.

Last week, her boyfriend Travis Kelce unfollowed Reynolds – who is currently celebrating his soccer team Wrexham’s promotion to the English Football League Championship – in yet another sign that relations between the two couples have cooled.

Although Kelce is unlikely to be slapped with a subpoena, one person who has already got one is publicist Stephanie Jones who is also being sued by Baldoni after she allegedly turned over a phone belonging to his publicist and her former employee, Jennifer Abel.

The messages on the phone between Abel and crisis PR Melissa Nathan were later used as the basis for Lively’s claims of a smear campaign, although Baldoni’s team hit back saying the texts were selectively edited and released the conversations in full.

Jones denied handing over the texts as a favor, arguing in court papers that she turned the device over only after receiving a subpoena last October.

But her claims led to fresh embarrassment for Lively after DailyMail.com revealed the subpoena had arisen from a ‘sham’ lawsuit filed by her company Vanzan against anonymous Does 1-10 which was dropped before the 37-year-old’s sex assault case was filed.

The revelation prompted a furious response from Baldoni’s lawyer Bryan Freedman who described the Vanzan suit as a ‘sham’.

‘Ms. Lively’s and Mr. Reynolds’ company Vanzan had nothing to do with this case and they knew it,’ Freedman said in a statement.

‘This sham lawsuit was designed to obtain subpoena power without oversight or scrutiny, and in doing so denied my clients the ability to contest the propriety, nature, and scope of the subpoena.

‘There is nothing normal about this. Officers of the court have a duty of candor to the court and an obligation not to file fictitious lawsuits that have no basis in fact or law. 

‘This was done in bad faith and constitutes a flagrant abuse of process.’

Last week, DailyMail.com revealed that the superstar singer was left devastated when she was subpoenaed as a witness in the case. 

Despite putting on a brave face in Philadelphia this weekend – reportedly joining her boyfriend Travis Kelce and their respective moms for a Mother’s Day lunch – it is understood that Swift, 35, has been ‘completely floored’ by the legal escalation and is now ‘very upset’. 

And not least because she feels betrayed and ‘exploited’ by her longtime friend, Lively.

Up until this year, Swift counted Lively, 37, among her closest confidantes. 

They live just a stone’s throw away from each other in New York’s trendy Tribeca neighborhood, and Swift is godmother to Lively’s three daughters. 

But things soured in December when Lively sued Baldoni, her co-star and director in the It Ends With Us movie adaptation of the popular Colleen Hoover novel. 

The following month, when Baldoni filed a countersuit accusing Lively and her husband Ryan Reynolds, 48, of defamation, Swift was dragged into the mix.

Contained in Baldoni’s filing were screenshots of text messages and emails that named Swift. 

One particularly uncomfortable exchange allegedly shows Lively referring to herself as Khaleesi – a character in Games of Thrones – and to Swift as one of her ‘dragons’.

Baldoni also claimed that Swift was present at a pivotal meeting about the movie, held by Lively and Reynolds at their New York penthouse. 

For her part, a source close to Swift has said she simply arrived to find the meeting underway and had no involvement.