ALBURGH, Vt. (AP) — A Vermont man is charged with spraying liquid manure on a marked U.S. Customs and Border Protection car after confronting an agent about immigration enforcement.

Fifty-three-year-old Mark Johnson, of Alburgh, is due in court Thursday to answer charges of assault and disorderly conduct.

Johnson told The Associated Press on Wednesday that the agent was parked at the entrance to a field near the Canadian border where Johnson was spreading manure Aug. 3. He says he asked the agent why authorities weren't doing more to arrest immigrants who are in the country illegally and working on Vermont farms. He says the agent was rude.

Johnson says he didn't know the car was behind him when he turned on his spreader.

Agency spokeswoman Stephanie Malin says Vermont prosecutors are handling the case.