The feud between Elton John and Madonna has been fueled with vicious fire.

Reports say that during an interview with Australia's Channel 7 on Sunday, John, 65, shared his thoughts on the Queen of Pop's current MDNA tour -- and they weren't very nice.

"She's such a nightmare," he said. "Her career is over, I can tell you that. Her tour has been a disaster and it couldn't happen to a bigger c--t."

He also commented on Madonna's most recent album, MDNA, while insulting her looks and being rude to Lady Gaga and trying to give constructive criticism.

"If Madonna had any common sense, she would have made a record like Ray of Light, stayed away from the dance stuff, and just been a great pop singer and made great pop records, which she does brilliantly. But no, she had to prove that she was like . . ." John continued. "And she looks like a f-----g fairground stripper.

"She's been so horrible to [Lady] Gaga."

According to US magazine, the music legend's feud with Madonna, 53, has been going on for years, and in January Elton's husband, David Furnish, 49, also got involved. After Elton lost the Golden Globe Award for Best Original Song to Madonna, Furnish publicly slammed her acceptance speech.

"Madonna winning Best Original Song truly shows how these awards have nothing to do with merit. Her acceptance speech was embarrassing in its narcissism," he wrote on his Facebook page. "And her criticism of Gaga shows how desperate she really is."

In 2004, Elton laughed off a Q Awards nomination Madonna received for best live act, claiming she lip syncs in her performances, according to the LA Times.

Madonna never really takes the Elton bait though. The LA Times said that after the 2004 insult,

Madge rep Liz Rosenberg simply said, "Elton John remains on her Christmas card list."

After her Globes win, Madonna said she hopes Elton would continue to speak to her despite her victory, and that "he'll win another award though, so I don't feel bad."