The trial starting this week against Evan Greebel, a former Kaye Scholer and Katten Muchin Rosenman partner and onetime adviser to Martin Shkreli, will not only dive into federal conspiracy charges, but also explore at what point federal prosecutors claim ethical violations by a lawyer can become a crime.

In battling letters on the eve of trial to U.S. District Judge Kiyo Matsumoto in Brooklyn, Greebel’s defense lawyers assert that the government is apparently contending that violations of attorney ethics rules relate to its criminal prosecution.