WBA heavyweight champion David Haye has branded Wladimir Klitschko a "coward" for opting to fight Dereck Chisora, Sky Sports reported Thursday.
Haye had looked set for a unification showdown with IBF and WBO title-holder Klitschko after lengthy negotiations with the Ukrainian.
But Klitschko has announced that he will now fight Haye's fellow Londoner Chisora on April 30 in Germany.
It left Haye angry after the 30-year-old had agreed to every concession Klitschko had wanted in order for the fight to happen.
Haye said in a statement: "We agreed to a date of July 2 at a venue in Germany with both Sky Sports and [European entertainment network] RTL and everybody appeared happy with the deal.
"We made a few concessions to remove past stumbling blocks and were happy to do so, as it finally looked like the fight would get made.
"Even through negotiations, though, it was clear Wladimir was looking for the coward's way out. He would often come up with new obstacles and problems to overcome, and I never once sensed he fancied it.
"He refused to come to England, wanted to pick his own gloves, enter the ring second, box out of the red corner and demanded a German doctor.
"He also wanted his name to feature first on any promotional material ahead of the event. We bowed to each and every one of his demands. I didn't want to potentially jeopardize anything this time around."
Klitschko has denied that the fight is off, insisting he will fight Haye on July 2 as planned after he has taken on Chisora, who he was originally due to face in December before injury saw the bout postponed.
Haye dismisses those claims, saying there is no way Klitschko will have two fights in nine weeks having fought just three times in two years.
"If the fight doesn't happen now, it never will. I'm done with the Klitschkos," Haye said. "I know I can retire later this year with my head held high, knowing I did everything in my power to make these fights happen."
