It may be dirty laundry day today in the Sean "Puffy" Combs gun-rap case.

Prosecutors are poised to discuss at length the music mogul's bad-boy past, just in time for an expected crush of press attention.

The DA's team is expected to argue in court that Combs' brushes with the law over fist fights and guns are fair game should he take the stand in his trial in connection with a December 1999 Midtown club shoot-'em-up. 

But defense lawyers have fought bitterly against a public detailing of a record that includes Combs' admitted 1999 beating of rival rap producer Steven Stout. 

Prosecutors may also air more details of allegations that over the past five years, Combs brandished guns during fights in New York and Washington and had a habit of leaving stolen guns behind in hotels and rental Rolls-Royces like so many forgotten umbrellas. 

The crowd of press expected to lap up such details today, including reporters from MTV, Entertainment Tonight, and Extrais just a preview of the media feeding frenzy expected Monday. 

That's when Combs, his bodyguard Anthony "Wolf" Jones, and his protégé rapper Jamal "Shyne" Barrow go on trial in the club shooting that put three bystanders in the hospital. 

Manhattan Supreme Court Justice Charles Solomon is scheduled to hear arguments over how much prosecutors could grill all three defendants on their arrest records if they take the stand. 

Defense lawyer Murray Richman said he plans to file a motion today asking the judge to prevent Assistant District Attorney Matthew Bogdanos from confronting his client, Barrow, with his pistol-packed rap lyrics. 

Combs defense lawyer Benjamin Brafman denied press accounts that he'd put the rapper's screen siren girlfriend, Jennifer Lopez, on a witness list. 

"No witness list has been given to the court or the prosecutor," Brafman said, adding that he has refused to discuss potential witnesses.