(CNN) -- The fight boxing fans have long been clamoring for has moved a step closer, with undefeated Floyd Mayweather challenging Manny Pacquiao to a showdown on May 5 -- but will it happen?
Hopes of the much-anticipated bout dimmed in December when Mayweather, the WBC welterweight champion, was sentenced to a 90-day prison term after being found guilty of domestic violence.
However, a Nevada judge ruled last week that the American, who has won all 42 of his professional fights (26 by knockout), could delay reporting to jail until June because he had already lined up a fight in May.
And now the 34-year-old has revealed he wants his opponent to be the Philippines' WBO champion -- his longtime rival for the title of best pound-for-pound boxer, and a man he failed to agree a deal with in 2010 after insisting on Olympic-style pre-bout blood testing.
Mayweather chose micro-blogging website Twitter to issue his challenge.
"Manny Pacquiao I'm calling you out let's fight May 5th and give the world what they want to see," he wrote on Tuesday.
"My jail sentence was pushed back because the date was locked in. Step up punk."
However, Pacquiao -- who retained his WBO title in his third meeting with Juan Manuel Marquez in November -- issued a statement via his website saying he does not want to fight on that date.
"Manny Pacquiao wants to make it clear the fight can happen at the end of May -- Manny wants Floyd to release his grip on May 5th, so the fight can happen for the fans," Wednesday's statement read.
Pacquiao has an impressive record, with 54 wins from 59 bouts -- 38 by knockout -- plus three losses and two draws. He is the first man in the sport's history to have won world titles in eight weight divisions.
The 33-year-old is rated by Ring Magazine as the best pound-for-pound fighter in the world, with Mayweather second on the 10-man list following September's knockout win over compatriot Victor Ortiz in Las Vegas.
Pacquiao has also launched a successful political career and was elected into the Philippine House of Representatives in June 2010.