Attorney General John Ashcroft is making it tougher for federal prosecutors to strike plea bargains with criminal defendants. In a memo sent to all 94 U.S. attorneys’ offices yesterday, Ashcroft ordered Federal prosecutors to pursue maximum criminal charges and sentences whenever possible and to seek lesser penalties through plea bargains only in limited circumstances. A past president of the National Association of Criminal Defense Lawyers, said the change “creates a system that is not only inflexible and problematic, but becomes a sort of immovable object. You’re adding more unfairness to the system.” During the summer Ashcroft instructed U.S. attorneys to seek the death penalty whenever applicable and announced a plan last month to track data on judges who give lighter sentences than recommended by federal guidelines.