As a trial approaches for the former Mashantucket Pequot chairman charged with stealing more than $100,000 in tribal funds, federal prosecutors are moving to block a potential defense strategy, arguing he should not be allowed to claim he was acting in good faith and intended to repay the money.

Michael Thomas, who was chairman from 2003 to 2009, has pleaded not guilty to charges that he stole from the tribe, which owns and operates the Foxwoods Resort Casino in southeastern Connecticut. His trial is to begin July 22.