Taylor Swift just took her gloves off in her ongoing Katy Perry feud

Musicians Kary Perry and Taylor Swift in 2010. Photo / Getty

Just when we thought the long-running Taylor Swift / Katy Perry feud couldn't get any pettier ...

The years-long rivalry between the two pop queens has been the subject of much media attention lately, as Perry's geared up for the release of her first album in four years, Witness, out today.

Her latest single, Swish Swish, is a pretty brazen diss track directed in Swift's direction, and in interviews to accompany the album she hasn't been shy about discussing her beef with Swift.

Now Swift - publicly silent for most of 2017 as she works on new music - has pulled a breathtakingly audacious move.

The country-pop superstar famously pulled all her music from streaming giant Spotify in 2014, arguing at the time that "valuable things should be paid for". It meant that the millions of Spotify users and casual Taylor Swift fans who want to hear her music would have to buy, rather than stream, her albums.

It seems that Tay-Tay and Spotify have made up, because she's just announced that her entire back catalogue will once more be made available on all streaming services ... from midnight tonight.

To be clear, that's exactly the same time Katy Perry drops Witness in the US, her biggest market (the album was made available here in Australia at midnight last night).

According to Swift's announcement, Taylor's sudden streaming backflip is "in celebration of [latest album] 1989 selling over 10 million albums worldwide" and a way for her to "thank her fans".

The fact that streaming services will suddenly become flooded with previously unavailable Taylor Swift hits at the exact same time Katy Perry's trying to get her new album heard? Why, surely that's a complete coincidence.

❤️❤️❤️❤️❤️ pic.twitter.com/kcpY03qHLp

— Taylor Nation (@taylornation13) June 8, 2017

This is the last thing Perry needs as she launches her new album to an inarguably lukewarm reception. At the height of her pop powers, Perry scored a record-breaking six US number one singles from 2010's Teenage Dream album.

By contrast, the two singles immediately preceding Witness have so far peaked outside the US top 40.

In her latest public statement directed Swift's way, Perry accused her pop rival of trying to "assassinate her character".

"I mean, I'm not Buddha - things irritate me," she said in the latest issue of NME.

"I wish that I could turn the other cheek every single time, but I'm also not a pushover, you know? Especially when someone tries to assassinate my character with little girls [her fans]. That's so messed up!"