NEW YORK — Rep. Chris Collins, a Republican congressman from western New York, is resigning from his seat ahead of an expected guilty plea in an insider trading case in which he was accused of leaking confidential information during an urgent phone call made from a White House picnic.

Collins submitted a resignation letter Monday, according to a spokesman for House Speaker Nancy Pelosi. It will take effect when Congress meets in a brief session on Tuesday.

A federal judge in Manhattan scheduled a hearing for Collins to enter a guilty plea to unspecified charges in the case Tuesday afternoon. A similar hearing has been scheduled Thursday for the congressman’s son, Cameron Collins.

Collins’ congressional office declined to comment on Monday. His attorney didn’t immediately respond to a message. The U.S. attorney’s office in Manhattan also declined to comment.

Collins had been scheduled to go to trial next year. Prosecutors accused him of sharing non-public information from a biopharmaceutical company with his son, allowing Cameron Collins and another man to avoid nearly $800,000 in stock losses.