SAN FRANCISCO – Barry Bonds asked a federal judge Monday to toss out most of the government's case against him that charges the slugger lied to a federal grand jury about his alleged steroids use.

In a filing made in U.S. District Court in San Francisco, lawyers for baseball's home run king argue that many of the charges stem from ambiguous answers to ambiguous questions posed by prosecutors.

Bonds is charged with 14 counts of making false declarations to a grand jury in December 2003 and one count of obstruction of justice. His lawyers on Monday asked a judge to toss out 10 charges. He has pleaded not guilty to all counts and is scheduled for trial on March 2.

The 44-year-old Bonds, an unsigned free agent, hit .276 last year with 28 home runs, 66 RBIs and a major league-high 132 walks. He doesn't admit nor deny using steroids in the latest court filing.

Instead, Bonds' lawyers argue that “the questions posed to Mr. Bonds by two different prosecutors at his grand jury appearance were imprecise, redundant, overlapping and frequently compound.”

For instance, they argue that when Bonds denied if he had “taken anything like” steroids, he was answering a “fundamentally ambiguous” question.

A spokesman with the U.S. Attorney's office in San Francisco declined comment.

The 15 counts pending against Bonds are contained in a second federal indictment charging Bonds with repeatedly lying when he testified that he never used performance-enhancing drugs.

A federal judge threw out the first indictment and ordered prosecutors to draft a new one after she found some charges contained multiple allegations. The superseding indictment charged Bonds with making “false declarations” instead of “perjury.”