SAN FRANCISCO — Prosecutors took what could be a final swing at Barry Bonds, saying he deserves a “significant” jail sentence for “corrupt” behavior for which he still hasn’t taken responsibility.

In a filing Thursday, the U.S. attorney’s office asked for a 15-month prison term and objected to a pre-sentence report recommending two years’ probation, a punishment below the advisory guidelines. The defense on Tuesday had concurred with the report, saying a term of probation would be appropriate.