Rep. Grimm to Resign After Guilty Plea to Tax Charge

John Boehner and House Republicans pushed Grimm to step down, GOP advisers say.

— -- Rep. Michael Grimm, who pleaded guilty to a felony tax charge in federal court last week, plans to resign his seat in the U.S. House of Representatives on Jan. 5, he announced in a statement.

"This decision is made with a heavy heart, as I have enjoyed a very special relationship and closeness with my constituents, whom I care about deeply," he said in the statement, which was released late Monday.

"The events which led to this day did not break my spirit, nor the will of the voters. However, I do not believe that I can continue to be 100% effective in the next Congress, and therefore, out of respect for the Office and the people I so proudly represent, it is time for me to start the next chapter of my life."

Speaker John Boehner and House Republican leadership pushed Grimm to step down, two senior GOP advisers told ABC News. Grimm had hoped to keep his seat, at least for a while in the wake of pleading guilty to tax fraud, but Republican leaders "gave him no choice," aides said.

The speaker and Republican leaders were eager to put the matter behind them before the new session of Congress begins next week.

Last week, Grimm told reporters outside the courtroom that he would not resign.

"As I said before as long as I am able to serve I will serve," he said.

Grimm pleaded guilty to a single count of aiding in the preparation of a false tax return in 2009 and also agreed to pay an undetermined amount of restitution to the IRS and New York State on tax returns dating from 2007 to 2010. Grimm faces a maximum sentence of three years in prison and is set to be sentenced on June 8 in arguably the highest-profile public corruption case in New York in decades.

The Staten Island Republican told reporters after the hearing that he made some "big mistakes,” explaining that he "under-reported" sales receipts to pay business expenses, including compensating employees "off the books."

"As a result the taxes were inaccurate," Grimm admitted. "It's wrong...I should not have done it."

Grimm is also alleged to have solicited and accepted prohibited campaign contributions, caused false information to be included in campaign finance reports and allegedly made a deal with a foreign national to collect campaign contributions in exchange for help getting a green card.

"As an elected official, Grimm was responsible for deciding how taxpayers' money should be spent, yet he chose not to pay his fair share of taxes while operating his business," George Venizelos, Assistant Director in Charge at the New York Field Office, wrote in a statement. "Adding insult to injury, while serving as a Member of Congress, Grimm lied under oath in an effort to conceal his criminal activity. The public expects their elected officials at all levels of government to behave honorably, or at a minimum, lawfully. As his guilty plea demonstrates, Grimm put self-interest above public service."

Plea negotiations had dragged on for months. Sources indicated the case against Grimm was "solid" but "not good for the bureau" given Grimm's history as a former FBI agent.

Grimm was slated to be sworn into a third term in office on January 6.

Even before the court appearance, Democrats seized on the expected admission of guilt, calling on Grimm to resign from his seat in the House of Representatives.

House Speaker John Boehner's spokesman Michael Steel said Boehner “won't have any announcements until the Speaker discusses the matter with Mr. Grimm."

ABC News' Mike Levine and Josh Margolin contributed to this report.