As part of a series of exclusive online interviews with Joe Calzaghe, the world champion talks about the one aspect of his sport that frustrates him.

"I would love to see boxing return to the era when a fighter could unify all the belts. That is practically impossible now. There are too many belts, too much politics and too much bullshit from promoters. It is has affected my career and it is bad for the sport.

"I remember when Bernard Hopkins agreed to fight me, only for his promoter to turn around and double the money they wanted. Suddenly, it was six million instead of three. It was bullshit, he didn't want to fight me. I have had happen often. Steve Collins said he was injured when he pulled out of a defence and retired, but he just didn't want the fight. I really believe that.

"For a long time I held the WBO title, which is not one of the most prestigious belts, but I defended it against six world champions and that was good enough for me. I wanted one of the bigger belts but, for years, I either got injured or the other fighter didn't want to know. Eventually I beat Jeff Lacy and took his IBF belt. People doubted my ambition but I proved them wrong that night.

"Now, I would love to be the unified champion but it won't happen, it can't happen."

Joe Calzaghe: No Ordinary Joe is published in hardback by Century on May 24, priced at £18.99

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