Rep. Chaka Fattah, D-Pennsylvania, is resigning effective immediately, he said in a letter to House Speaker Paul Ryan.

"Upon reflection, I hereby make official my resignation from the U.S. House of Representatives effective immediately," he wrote.

The letter, written Thursday, after his conviction on a total of 22 separate accounts including racketeering, fraud and money laundering on Tuesday, reversed course on a letter he had sent Ryan on Wednesday that stated he would wait until Oct. 3 -- a day before his sentencing -- to resign, given his intent to appeal his conviction.

But with growing objections to delaying his resignation, Fattah on Thursday sent the revised letter to the speaker. His immediate resignation was first reported by the Philadelphia Inquirer and confirmed by CBS News.

"Out of respect for the entire House leadership, and so as not to cause a distraction from the House's work for the people, I have changed my effective [resignation] date," he wrote to Ryan.

In July 2015, the first indictments were brought up against the former veteran U.S. representative as well as four of his colleagues for embezzling hundreds of thousands of dollars in campaign funds, charitable donations and federal funds after a failed 2007 Philadelphia mayoral bid.

In a statement Wednesday evening, speaker Ryan was adamant about insisting on Rep. Fattah's immediate resignation.

"Mr. Fattah has betrayed the trust of this institution and the people of Pennsylvania, and for that he should resign immediately from the House of Representatives," Ryan said. "We must hold members to the highest ethical standard, and I hope that Democratic leaders will join me in seeking his immediate resignation."

Then, Philadelphia Republicans further seized on Rep. Fattah's original plan to hold off on his resignation despite his conviction.

Joseph F. DeFelice, Philadelphia GOP chairman, said he was "ensuring he can collect a paycheck while continuing to do nothing to benefit his constituents."

While he considered the timing of his resignation, Minority Leader Nancy Pelosi called Fattah's conviction "heartbreaking" and said, "I think he should think it through and he'll let us know."

Fattah served as a U.S. congressman since 1995. Last year, when he was indicted, Fattah had to step down as top Democrat on the Appropriations Subcommittee on Commerce, Science and Justice.

His sentencing is set for October 4, and until then, remains free on bail.