Justin Bieber has accused Taylor Swift of attempting to “get sympathy” as the Pop titans publicly rowed over the sale of the country music’s stars back catalogue.

The 29-year-old attacked Bieber’s manager Scooter Braun on Sunday for buying the rights to much of her multi-platinum back catalogue.

In a blog post, Swift said she suffered years of “manipulative bullying” by Braun, an industry powerhouse whose company recently bought Big Machine Label Group, which produced her first seven albums.

“Essentially, my musical legacy is about to lie in the hands of someone who tried to dismantle it,” Swift wrote, claiming she had never been offered the chance to buy the rights to her early work.

Describing it as the “worst case scenario”, she said the body of work is “beholden to men who had no part in creating it”.

In 2018 Swift left Big Machine, whose current chief executive is Scott Borchetta, to move to Universal Music Group, the label that’s behind her upcoming album “Lover”.

Big Machine announced on Sunday that it had been acquired by Braun’s Ithaca Holdings.

Swift claimed she heard the news “as it was announced to the world”, attacking the sale and re-igniting a long-standing feud with Braun and two of his clients, Justin Bieber and Kanye West.

Tensions between West and Swift date back to the rapper’s infamous interruption of a 2009 award acceptance speech and intensified in 2016 when Swift claimed she was not consulted about Kanye’s plan to name-check her in a song. West’s wife Kim Kardashian later disputed the claim by producing a secret recording in which Swift appeared to agree to be mentioned. Bieber then weighed into the controversy by posting an image of himself on a video call with Braun and West on social media with the caption “Taylor swift what up.”

On Sunday Bieber took to Instagram to defend Braun, who also manages pop star Ariana Grande. “For you to take it to social media and get people to hate on Scooter isn’t fair,” the Canadian superstar wrote, posting the message alongside an old photograph of himself and Swift.

“Seems to me like it was to get sympathy u [sic] also knew that in posting that your fans would go and bully Scooter.”

Swift’s huge social media presence is powered by legions of fiercely loyal fans – known as “Swifties” – who frequently round on those perceived as slighting her.

“When you try and deface someone I loves character that’s crossing a line [sic],” Bieber, 25, wrote.

Scott Borchetta and Scooter Braun pose for a photo at a private residence in Montecito, California CREDIT: Getty

Meanwhile Swift’s former label boss, Scott Borchetta, claimed he had personally texted the singer a day before news of the sale broke, adding that her father is a shareholder in Big Machine and was notified of the sale on June 25th.

In a statement, Borchetta said: “I truly doubt that she ‘woke up to the news when everyone else did’.”

Borchetta also claimed the country music star declined to perform at a charity concert for victims of the Manchester Arena terror attack.

The One Love Manchester concert organised by Braun to fundraise for victims of the bomb blast at Ariana Grande’s concert in May 2017, when 22 people were killed and hundreds injured.

Borchetta said: “[Braun] called me directly about Manchester to see if Taylor would participate (she declined).

“He called me directly to see if Taylor wanted to participate in the Parkland March (she declined).

“Scooter has always been and will continue to be a supporter and honest custodian for Taylor and her music.”

A representative for Swift denied that she or her father had advance knowledge of the sale.  “On June 25, there was a shareholder phone call that Scott Swift did not participate in, due to a very strict NDA that bound all shareholders and prohibited any discussion at all without risk of severe penalty,” the spokesperson told Variety magazine.

“Her dad did not join that call because he did not want to be required to withhold any information from his own daughter. Taylor found out from the news articles when she woke up before seeing any text from Scott Borchetta, and he did not call her in advance.”