Nathan Cleverly branded Carl Froch an "absolute joke" for claiming to be one of the best British boxers ever.
The 26-year-old's promoter Frank Warren said Froch had turned down a £2.5m offer to take on Cleverly without putting his IBF and WBA world super-middleweight championship belts on the line.
"I have a lot of respect for Froch, but the idea of him being the best British fighter ever is an absolute joke," Cleverly said. "That's disrespectful to Joe Calzaghe, who would have boxed Froch's head off.
"He is slow, robotic, and he is claiming he is the best British fighter ever... it's just idiotic."