Tyson Fury says his proposed heavyweight showdown with Anthony Joshua is off after his self-imposed deadline expired.
Fury set Joshua's camp an ultimatum on Friday night, insisting if the deal could not be done in time then he would walk away from the blockbuster all-British bout.
Speaking on Instagram on Monday evening, the WBC champion said: "Well guys, it's official. D-day has come and gone. It's gone past five o'clock, Monday. No contract has been signed.
"It's officially over for Joshua. He is now out in the cold with the wolfpack.
"Forget about it. Idiot. Coward. S***house. Body builder. Always knew it. Always knew you didn't have the minerals to fight the Gypsy king.
"Regardless of what the f*** you say now, I don't really care. Good luck with your career, and your life. End of. Peace out."
Promoter Eddie Hearn had already said there was "no chance" of contracts for being signed by Monday, while Joshua insisted on Sunday that the negotiations were down to his lawyers.
Speaking on an Instagram Live, Joshua said: "It ain't in my hands - it's with a legal team. That's why you hire lawyers.
"You know the history of boxing - make sure you get your legal terms right. That's why you get good management and good lawyers.
"So of course I'm going to sign the contract - it's just with some lawyers at the minute."
Television executives from BT Sport and streaming service DAZN were scheduled to meet on Monday, with Joshua's team having already verbally accepted Fury's offer of a 60-40 purse split.
Joshua suffered a second consecutive defeat to Oleksandr Usyk in Saudi Arabia last month, and Fury's hopes of a match against the Ukrainian were dashed after he indicated he does not intend to return to the ring until 2023.