Kell Brook has claimed Amir Khan "doesn’t want" to fight despite renewed hope that an agreement could finally be reached.
Khan had claimed "I want to fight the top names" in the build-up to his next bout, against former featherweight world champion Billy Dib on July 12 in Saudi Arabia.
"Amir Khan doesn't want the fight, he talks c**p," Brook told Sky Sports. "I haven't got time for time wasters."
Brook and Khan have failed to agree a much-anticipated fight for years, but neither have any plans to retire yet so hope remains that they could still meet.
"The Brook fight is still out there, definitely," Khan told Sky Sports News earlier this month. "In Britain it would be a huge fight.
"There are still a lot of fights that [promoter Eddie Hearn] can make for me. I want to fight the top names."
The British rivals appeared closer than ever to agreeing a fight earlier this year, but Khan instead chose to challenge Terence Crawford for the WBO title, suffering a sixth-round stoppage defeat in New York in April.
"I've still got it - I feel strong and sharp," Khan said afterwards.
He was scheduled to face India's Neeraj Goyat, who withdrew after sustaining injuries in a car crash, and Australia's Dib has stepped in as a late replacement after agreeing to move up three weight classes for the fight.
Brook, meanwhile, rejected rumours that he would retire, insisting he wants more "special nights" in his career.
"I have not retired," Brook posted on social media. "I have had some time away from the ring but me and my team have been proactively looking to secure big fights."