Tyson Fury has branded Oleksandr Usyk a ‘coward’ (Image: Instagram/Getty)

Tyson Fury has launched a scathing attack on Oleksandr Usyk after talks about their unification struggle fell through this week.

Fury and Usyk lined up to fight for all four heavyweight belts at Wembley Stadium on April 29.

However, negotiations for the event stalled this week due to a problem with the rematch clause.

Usyk had initially accepted Fury’s request for a 70/30 split, but no deal could be reached after the Ukrainian asked for the same split to be used to his advantage for the rematch, provided he took the first fight at Wembley to win.

Fury, who began training earlier this month, now has no opponent, while Usyk is expected to be in talks with his WBA heavyweight title contender Daniel Dubois, who is still recovering from the ACL injury he sustained in December.

Oleksandr Usyk and Tyson Fury are both looking for new opponents after talks about their unification battle broke down this week (Getty)

“Usyk, you little bastard, you real little bastard, dirty eyes, gaping teeth, ugly little rat bastard. You little slimy bastard,” Fury said in a message to Usyk on Instagram.

“I’ve been trying to come out all week, begging like a little girl for a rematch. You got your rematch and you didn’t even want to fight for it. You little bastard.

“Always know, P****, you were never man enough to quarrel with the gypsy king, never in your life, you little bastard.

“You little coward, you little bastard, you little bastard, and your whole team knows it too, and all the lawyers have the full information, you ugly little bastard.

‘Keep on running. Fight Dubois at the Copper Box [Arena] Now, asshole. And always know that you, or someone like you, will never come into contact with the gypsy king, you little coward.