By JOHN M. BRODER
LOS ANGELES, Nov. 28 - Representative Randy Cunningham, a Republican from San Diego, resigned from Congress on Monday, hours after pleading guilty to taking at least $2.4 million in bribes to help friends and campaign contributors win military contracts.
Mr. Cunningham, a highly decorated Navy fighter pilot in Vietnam, tearfully acknowledged his guilt in a statement read outside the federal courthouse in San Diego.
"The truth is, I broke the law, concealed my conduct and disgraced my office," he said. "I know that I will forfeit my freedom, my reputation, my worldly possessions and, most importantly, the trust of my friends and family."
Mr. Cunningham, 63, pleaded guilty to one count of tax evasion and one count of conspiracy to commit bribery, tax evasion, wire fraud and mail fraud. He faces up to 10 years in prison and hundreds of thousands of dollars in fines and forfeitures.
Prosecutors said he received cash, cars, rugs, antiques, furniture, yacht club fees, moving expenses and vacations from four unnamed co-conspirators in exchange for aid in winning military contracts. None of this income was reported to the Internal Revenue Service or on the congressman's financial disclosure forms, the government said.
Mr. Cunningham, who is known as Duke, lived while in Washington on a 42-foot yacht, named the Duke-Stir, owned by one of the military contractors that received tens of millions of dollars in federal contracts that prosecutors said Mr. Cunningham helped steer its way.
Mr. Cunningham, who is known for his combative conservatism and his emotional outbursts, served on the defense subcommittee of the House Appropriations Committee and as chairman of the House Intelligence subcommittee on terrorism and human intelligence.
"He did the worst thing an elected official can do," Carol C. Lam, the United States attorney, said in a statement. "He enriched himself through his position and violated the trust of those who put him there."
Mr. Cunningham's plea adds to the ethics cloud over the Republican-controlled Congress and the Bush White House.
In the Senate, Bill Frist, Republican of Tennessee and the majority leader, is under scrutiny by the Securities and Exchange Commission for the timing of his trades in the stock of his family's health care company. In the House, Representative Tom DeLay, Republican of Texas, was forced to step down as majority leader after he was indicted on conspiracy and money laundering charges in his home state.
In a separate Justice Department investigation, Michael Scanlon, a former spokesman for Mr. DeLay, pleaded guilty last week to bribery. Prosecutors said Mr. Scanlon was part of a conspiracy to defraud Indian tribes and win legislative favors from lawmakers in return for campaign donations, meals, entertainment and other benefits. A former White House aide has also been indicted in that investigation, which is centered around Jack Abramoff, a lobbyist and ally of Mr. DeLay who worked with Mr. Scanlon. As part of his plea, Mr. Scanlon agreed to cooperate in the investigation.
In addition, I. Lewis Libby Jr., the former chief of staff to Vice President Dick Cheney, was indicted last month for perjury and false statements in the investigation of the leaking of the name of a C.I.A. operative. Other White House officials, including the senior political adviser Karl Rove, remain under investigation in that case.
Democrats in Congress hope that the legal and ethical woes afflicting Republicans will weaken the party in policy debates and at the polls next November. Representative Nancy Pelosi of California, the House Democratic leader, called Mr. Cunningham's acceptance of bribes an "egregious act" that was symptomatic of Republican values.
"This offense is just the latest example of the culture of corruption that pervades the Republican-controlled Congress, which ignores the needs of the American people to serve wealthy special interests and their cronies," Ms. Pelosi said in a statement.
The charging document said that in addition to the other gifts and services, Mr. Cunningham received from several unnamed co-conspirators a Rolls Royce, a graduation party for his daughter, a $200,000 down payment on a condominium and the payment of capital gains taxes on the sale of his home.
Federal authorities said that Mr. Cunningham was cooperating with the continuing investigation and that further charges involving the bribery conspiracy were likely.
Mr. Cunningham entered his plea before Judge Larry A. Burns of the United States District Court for the Southern District of California. He was fingerprinted and photographed and released on his own recognizance.
Judge Burns set sentencing for Feb. 27. Mr. Cunningham, in his statement, said he expected to do time in prison. "In my life, I have known great joy and great sorrow. And now I know great shame," he said. "I cannot undo what I have done. But I can atone."
Under California law, Gov. Arnold Schwarzenegger has 14 days to call a special election to fill Mr. Cunningham's seat. The election must occur within 120 days.
Mr. Cunningham's troubles began last summer when the Copley News Service and The San Diego Union-Tribune reported that Mitchell J. Wade, the founder of MZM Inc., a military contracting firm, bought Mr. Cunningham's home in Del Mar for $1,675,000 in 2003 and sold it nine months later for $975,000, a $700,000 loss.
Mr. Cunningham denied any wrongdoing in the house sale, but announced a few weeks after the reports appeared that he would not seek a ninth term in Congress in November 2006.
Mr. Cunningham used the profits from the sale to buy a luxury home in Rancho Santa Fe for $2.55 million, which he and his wife, Nancy, have since put up for sale. Under the plea agreement announced on Monday, he will forfeit the Rancho Santa Fe house and nearly $2 million in cash and home furnishings.
Carl Hulse contributed reporting from Washington for this article.
