Tyson Fury's father John has issued Dillian Whyte with an ultimatum telling him to drop the "mind games" and sign the contract.
Fury has been set to face Whyte ever since he was ordered to defend his WBC heavyweight title against his rival in his next contest.
However an official announcement has yet to be made with a contract row continuing after Frank Warren won purse bids with a bumper £31 million offer.
Fury's dad has now posted a message on social media to Whyte, warning: " Dillian Whyte you said you wanted a title shot and you have been banging on for three years that you haven't got it, and now you don't seem to want it pal.
"I don't know what mind games you are trying to play but they don't work with us. You are running out of time and you are making yourself look very stupid.
"Get the contract signed, get your beating along with your job. At least your consolation prize is $8 million, if you decline that you want putting in an asylum.
"Be a man and sign the contract and show us you are a man pal. God bless and we will see you at the press conference if you are a man."
Whyte has remained silent since purse bids were declared and won by Warren, as he continues to remain unhappy with the terms of the fight contract.
The purse split was declared at 80 per cent in the favour of the champion which is understood to have upset Whyte who is chasing further financial reward.
Fury has issued multiple warnings to Whyte on social media to "sign the contract" which Eddie Hearn has confirmed the 'Body Snatcher' has received.
The 'Gypsy King' has now claimed on social media that his rival is demanding further payment for attending a press conference to announce the fight.
"I just heard that little sausage Dillian Whyte wants paying to turn up for a press conference," Fury said during a video. "You little silly fat sausage, you’re getting that [a fist], you coward."
Who will win this year - Tyson Fury or Dillian Whyte? Let us know in the comments section below
He later continued: "Hi guys, just a quick one. I'm setting up a Just Giving page for Dilian Whyte so he can show up to the press conference and I'm going to donate first.
"My donation is 47p, you useless dosser."
Whyte has been demanding a shot at the WBC title since 2017 when he first became Silver champion with victory.
He could be set to earn up to $10 million for the clash if he can hand Fury his first defeat, with a 10 per cent bonus available for the winner.
Fury is set to earn a career-high guaranteed purse of $20 million which will also be raised if he can retain his title.
The winner is likely to go on and attempt to stage a tilt with the winner of Anthony Joshua's rematch against Oleksandr Usyk for the undisputed titles.
