New York - Taylor Swift's Bad Blood with fellow pop superstar Katy Perry looks set to get a lot worse.
Perry on Wednesday took to Twitter, where she has more followers than anyone else in the world, to take down Swift in a row set off by the nominations for the MTV Video Music Awards.
Rapper Nicki Minaj had voiced outrage that her Anaconda failed to be nominated for Video of the Year. She suggested that the music industry was biased against her as an African-American woman and preferred female stars "with very slim bodies."
If your video celebrates women with very slim bodies, you will be nominated for vid of the year ??????????????????????????
— NICKI MINAJ (@NICKIMINAJ) July 21, 2015
Swift, who received the most nominations for the 30 August awards, responded by inviting Minaj to join her on stage if Swift wins.
@NICKIMINAJ I've done nothing but love & support you. It's unlike you to pit women against each other. Maybe one of the men took your slot..
— Taylor Swift (@taylorswift13) July 21, 2015
@NICKIMINAJ If I win, please come up with me!! You're invited to any stage I'm ever on.
— Taylor Swift (@taylorswift13) July 21, 2015
The 30-year-old - who memorably sang "You're gonna hear me roar" - entered the fray a day later with clearly aiming her criticism at, without using her name.
"Finding it ironic to parade the 'pit women against other women' argument about as one unmeasurably capitalises on the takedown of a woman," she wrote to her nearly 73 million Twitter followers.
Finding it ironic to parade the pit women against other women argument about as one unmeasurably capitalizes on the take down of a woman...
— KATY PERRY (@katyperry) July 22, 2015
Uhm.. Sorry Katy what are you trying to say girl? #GrammarGoals!
Perry, in turn, then brought Rihanna's BBHMM video into the mix saying that the FourFiveSeconds singer is the one who really deserved a nomination.
The real travesty is where is the shine for #BBHMMVideo when VMA eligibility period was 7/7/14-7/1/15 & that gem dropped 7/1... @MTV
— KATY PERRY (@katyperry) July 22, 2015
Perry and Swift, often considered the era's two leading women in pop, have long been rumoured to have a poor relationship but it has rarely spilled into the open.
Swift was nominated for Video of the Year for Bad Blood, which depicts her as an action hero.
Swift has said that she wrote the song - with the lines "Now we got problems / And I don't think we can solve them" - about another pop star whom she accused of undercutting her by hiring people who had been working for her.
While Swift did not name her villain, she was widely believed to be referring to Perry.
(GIFs: Tumblr)