NEW YORK — U.S. Rep. Chris Collins, a Republican from western New York, submitted his resignation from Congress on Monday 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’ resignation will take effect when Congress meets in a brief session on Tuesday, according to a spokesman for House Speaker Nancy Pelosi.

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, who was among the first members of Congress to support President Trump’s run for the White House, had been scheduled to go to trial next year on charges of conspiracy, securities fraud, wire fraud and making false statements to the FBI. 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.

The case, filed in August of 2018, initially caused the 69-year-old Collins to drop a re-election bid, though he denied any wrongdoing and called the charges “meritless.”

But he restarted his campaign a month later as Republican leaders were deliberating who would replace him on the ballot.

At the time he said the “stakes are too high to allow the radical left to take control of this seat in Congress.”

The charges turned Collins’ expected easy re-election in a strongly Republican district into a close race, but he managed to fend off Democratic challenger Nate McMurray by a thin margin.

With his departure from Congress, it would be up to Gov. Andrew Cuomo to set a special election to fill the seat.

The charges stem from Collins’ business ties with Innate Immunotherapeutics Ltd., a biotechnology company headquartered in Sydney, Australia. He was the company’s largest shareholder, with nearly 17 percent of its shares, and sat on its board.

According to the indictment, Collins was attending the Congressional Picnic at the White House on June 22, 2017, when he received an email from the company’s chief executive saying that a trial of a drug the company developed to treat multiple sclerosis was a clinical failure.

Collins responded to the email saying: “Wow. Makes no sense. How are these results even possible???” the indictment said.

It said he then called his son, Cameron Collins, and, after several missed calls, they spoke for more than six minutes.

The next morning, according to the indictment, Cameron Collins began selling his shares, unloading enough over a two-day period to avoid $570,900 in losses before a public announcement of the drug trial results. After the announcement, the company’s stock price plunged 92 percent.

Cameron Collins is accused of passing along the information to his fiancée’s father, so he could also dump his stock.

The most serious charge carries a potential prison term of up to 20 years.