Maria Puente

USA TODAY

Kesha and Dr. Luke's bitter legal and professional quarrel careens on.

In the latest conflict, Kesha lost a gig — she was to perform at Sunday's Billboard Music Awards — because Dr. Luke's record label, Kemosabe Records (to which she is still tied), nixed its approval.

Why? It might have something to do with a report in TMZ and the New York Daily News last week, in which "sources close to Kesha" claimed she planned a performance in which she would diss Dr. Luke (real name: Lukasz Gottwald).

She denied this late Tuesday. Earlier in the day, a statement from dick clark productions, which produces the awards show, said that Kesha had accepted its invitation to perform at the show and "received written approval from Dr. Luke's label."

"Kemosabe subsequently rescinded its approval following a media report on Wednesday, May 11th regarding Kesha’s appearance on the BBMAs," the statement read. "Unfortunately, Kesha and Kemosabe have since been unable to come to an agreement for Kesha to perform on the show. dick clark productions has a long standing relationship with Kesha. We hope that the parties can come to an arrangement such that we can continue that long-standing relationship with a performance by Kesha on the Billboard Music Awards stage on May 22nd."

Oops.

If the two sides don't reach agreement before Sunday, Kesha loses out on a chance to appear on the same stage as Ludacris and Ciara, who will be hosting; with Madonna, who will be paying tribute to her pal Prince; with Britney Spears, who will get the Millennium Award for outstanding career achievement and influence in the music industry; and with Celine Dion, who will receive the ICON Award for her lifetime achievement and enduring contribution to popular music.

For the first time, the Billboard Awards will air live ( 8 p.m. ET) on ABC.

Kesha issued a statement late Tuesday on her Instagram page saying she had planned to perform a tribute to Bob Dylan with a cover of It Ain't Me, Babe, and denying that she planned to disparage Dr. Luke.

"I'm very sad and sorry to say I won't be allowed to do this," she said. "I just wanted to make very clear that this performance was about me honoring one of my favorite songwriters of all time and has never had anything at all to do with Dr. Luke. I was never going to use a picture of him, speak of him or allude to my legal situation in any way. I simply wanted to sing a song I love to honor an artist I have always looked up to. thank u all for the continued support."

Judge throws out Kesha's abuse claims vs. Dr. Luke

Kesha has been at war with Dr. Luke, her former producer and co-writer on many of her hits, for several years. She accused of him of drugging, sexually abusing and emotionally tormenting her and is suing him to get out of her contract with his label.

So far, she has failed to persuade a judge to agree with her, and Dr. Luke has vociferously denied her accusations.

She's been more successful on social media, where stars and fans have rallied round and tweeted encouraging words to her about her battle with Dr. Luke.

Dr. Luke's lawyer, Linda Carbone, declined to comment.

Celebs rally around Kesha as Dr. Luke calls claims 'outright lies'

Kesha has indicated on her social media accounts that things are looking up for her. On Sunday, she wrote on Instagram that she is "happy as a damn clam," despite "battling depression and an eating disorder for a while now."

"My career is in a strange place and it feels like I'm fighting an uphill fight some days. but I have decided to take my life back. my freedom. my happiness. my voice. my worth," she went on to write.