By Robert Lowe

Up-and-coming boxer Joseph Parker's promoter is continuing to chase a bout with Sonny Bill Williams, saying Williams should be stripped of his New Zealand PBA heavyweight belt if he doesn't accept.

However, NZPBA president Lance Revill says that, while it's a fight everyone wants, he doesn't see it happening in the immediate future.

Revill will formally put to Williams' manager, Khoder Nasser, the offer of a $1 million winner-takes-all challenge from Parker's promoter, Duco Events.

Duco is seeking a unification bout between Williams and the winner of the NZNBF title fight involving the highly rated Parker and defending champion Afa Tatupu in Auckland on Thursday.

Revill says that, on receipt of the offer, Williams has six months to defend the PBA title against any of the top top-10 contenders.

If the dual international wins that fight, he then has to put his crown up against the No.1 contender - who would be either Parker or Tatupu - within 12 months after that.

"To be fair to Khoder and Sonny Bill, I can't really see him accepting it within six months," Revill said of a bout against Parker.

"If I was Sonny Bill, I would need two or three fights to get myself in shape."

Williams, whose latest sporting exploit was helping the Sydney Roosters win an NRL premiership on Sunday, won the vacant NZPBA title when knocking out Clarence Tillman in February 2012.

The former All Black hasn't fought since a controversial win over South African Francois Botha in February, but is reported to be eyeing up a bout against 47-year-old Australian Bob Mirovic.

Williams, who has been tipped to return to rugby with the Chiefs, has said he will make a decision on his footballing future in the next couple of weeks.