Looks like there is no end in sight for the Lady Gaga and Madonna feud....

Tension has been brewing even more between the pair since Gaga rejected Madonna's offer to sing a duet with her. Speaking to the crowd at her Minnesota gig Madonna revealed that Gaga had rejected the opportunity to perform with her 'I invited her onstage to sing with me. But, she turned me down. It's okay. I've been rejected before. It builds a little character'. 'I have the best fans in the whole world. So take that, Lady GaGa!' she added.

The pair have been cat fighting for quite some time now. Earlier this year Madonna accused Lady Gaga of copying her claiming that 'Born This Way' had an resemblance to her 1989 hit 'Express Yourself'. Throughout her MDNA tour, Madge has been performing mash ups of the two songs highlighting the similarities between the songs. Madonna recently dedicated her song 'Masterpiece' to Gaga during a show in Atlantic city before saying 'You wanna know something? I love her. I love her. I do love her. Imitation is the highest form of flattery. But one day, very soon, we’re going to be on stage together. Just you wait. You think I’m kidding? I love Lady Gaga'. Looks like she will have to wait for that to happen now.

Madonna has sold over 17.8 million records since her 1984 hit 'Holiday' and was recently named the biggest selling female artist in UK history. She is currently coming to the end of the North America leg of her controversial MDNA tour.