The judge overseeing the upcoming Washington, D.C., trial of Paul Manafort told the government it can use evidence purportedly showing that Manafort was aware of rules that would have required him to register as a foreign agent for his work in Ukraine.

Manafort, President Trump’s former campaign chairman, is charged with violating the Foreign Agents Registration Act, as well as money laundering and obstruction of justice in the Washington case. Prosecutors plan to introduce evidence that shows that the Justice Department had advised him of the rules surrounding this type of work in the mid-1980s.

“The FARA unit made the defendant aware of the rules in ways that are particularly apt here,” prosecutor Andrew Weissmann told US District Judge Amy Berman Jackson during a hearing about the evidence Tuesday.