LIVERPOOL (WCMH) — Floyd Mayweather Jr. is challenging UFC lightweight champion Conor McGregor to a bout in June, and told a crowd in England he plans to come out of retirement.

ESPN reports Mayweather was speaking at an event in England, and urged the audience to film his announcement on their phones. The two have been talking back and forth about a potential bout, but nothing has ever been scheduled.

“I don’t know if it’s going to happen,” Mayweather told ESPN last week. “If Conor McGregor really wants the fight to happen, stop blowing smoke up everybody’s ass and sign the paper.”

Mayweather hasn’t fought since retiring in 2015. McGregor is taking a break from fighting, ESPN reports, and has filed for a license to box in California.

Bookies in Las Vegas favor Mayweather 25-1 if the bout were ever to happen.