Alexander Krassyuk, promoter for IBF, IBO, WBA, WBO heavyweight champion Oleksandr Usyk, has issued a firm warning to WBC champion Tyson Fury.

The two unbeaten champions are slated to collide on April 29th at Wembley Stadium, but Usyk's handlers are doubtful about Fury's eagerness to move forward with the date.

Last Friday, it was revealed that Usyk had accepted a 70-30 monetary split in Fury's favor.

"The negotiations now go live on Instagram, so we see both fighters exchanging messages," Krassyuk told Sky Sports News. "We are expecting to get some basic agreement with the terms and things like that but it's still pending. We've been negotiating for so many months. We went through all the small issues, bigger issues, large issues whatever.

"So it's all done already. It's been done actually several weeks ago. But the one thing that was pending was Tyson's consent, which is still pending. Though he claims he's ready and pretends he's training.

However, if the fight date moves due to Fury's inability or unwillingness to move ahead - then Usyk is no longer willing to accept a split of 70-30.

"We never mention anything like June or August, it's never been under discussion. Usyk was very clear in his message. April 29 I accept 70/30 [for the purse split]," Krassyuk explained.

"Egis Klimas [Usyk's manager] yesterday came out on Twitter saying that if it moves just for one day then it's going to be 50/50 again.

"I'm not really confident that this fight is going to happen on April 29, I will be surprised if it takes place, but if it takes place I will be really happy. Because this is the biggest thing Usyk wants, the baddest thing he wants in his life, to unify all the belts in the heavyweight division, the second division in his career."