Anthony Mundine has stepped up the war of words between himself and WBO welterweight champion Jeff Horn as the potential for a big domestic fight between the pair continues to grow.

Horn struck first on Thursday when he said he would happily fight a “past his best” Mundine for the “easy money”.

“Mundine is 42 now and he should have retired after his last fight against Danny Green. He’s past his best and if I can make a huge payday I’d be mad not to fight him before a Crawford bout,” Horn said.

That saw Mundine strike back with a claim that he would end Horn’s career, suggesting “it looked like he was on crack” during his win over Gary Corcoran.

“He doesn’t have the skill to beat me, I will end his career and his 10 minutes of fame,” Mundine told News Corp.

“After what I saw against Corcoran, Horn is a B-grade fighter. He looked like a drunken fighter at times, it looked like he was on crack, his feet were everywhere, he was all over the place.

“I am too strong, too fast, too seasoned. All he’s got going for him is his awkward style, but you saw what I did to the most awkward fighter in Australia, Sam Soliman, and I’ll destroy Horn the same way.”

It is understood that Horn is not required to fight mandatory challenger Terence Crawford until July, meaning that he could go up a weight class to face Mundine at light-middleweight before returning to welterweight for Crawford.

Boxing promoter Bob Arum wants Horn to face Crawford in Las Vegas on April 21, with the winner of that then likely to face Manny Pacquiao.

Mundine faces Tommy Browne on January 17.