MGM promoters in Vegas were planning on Taylor and Katy as joint headliners. Back to the drawing board on that eh.

All that Bad Blood between Taylor Swift and Katy Perry is causing a massive headache for concert promoters in Las Vegas.

Organisers of the launch of the $ 300 million MGM-AEG Arena were hoping the stars would jointly headline the venue’s opening night.

Now they’ve had to scrap their plans and choose between the two. Ouch.

One well placed executive at MGM reveals: “Initially it was suggested that both should headline, but that is impossible and neither would concede the headliner role.

“Now it’s up to MGM and AEG to decide who to pick – and that could be tricky given both are major players and earners.

“They are both in contention for the top spot on what will be a multi-million pound launch and one of the greatest events in the history of Vegas.

“AEG are keen to make sure that this new venue really gets huge traction. Early talks have started with their teams, but as you can imagine there is huge tension over it all – and the concert chain will have to make a decision.”

We don’t envy that job! The feud between Taylor, 25, and Katy, 30, kicked off when TayTay penned her track Bad Blood about the star, saying: “For years, I was never sure if we were friends or not.

“She would come up to me at awards shows and say something and walk away, and I would think: ‘Are we friends, or did she just give me the harshest insult of my life?

“Then last year, the other star crossed a line. She did something so horrible, I was like: ‘Oh, we’re just straight-up enemies’.”

Last week the row escalated when Katy tweeted about Taylor, after she had her own spat with Nicki Minaj, 32. Oh the drama.

The MGM-AEG Arena launches next Spring. Taylor will be fresh off the end of her 1989 tour while Katy will be releasing a new CD.

The venue – similar to London’s O2 – will be a huge cutting edge sports, concert and conference arena on the Strip.

We can’t wait to visit.