Todd Blanche, the acting attorney general, confirmed in writing on Sunday night that the Justice Department would abandon elements of the deal it struck with President Trump to resolve his lawsuit against the I.R.S., conceding to demands from Republican senators who had threatened to block his nomination as attorney general.

The Republican holdouts, Senators John Cornyn of Texas and Thom Tillis of North Carolina, had vowed that they would not confirm Mr. Blanche for the role unless he provided written assurances that the Justice Department had formally killed a planned $1.8 billion fund to pay those who claim they were unfairly persecuted by the government.

The senators also insisted that Mr. Blanche narrow the scope of the sweeping immunity from I.R.S. scrutiny that was granted to Mr. Trump, his family and their businesses under the same agreement.

Mr. Blanche posted two documents on social media on Sunday night: a signed memo in which he said that the Justice Department was formally rescinding an order that created the so-called “anti-weaponization fund” and an unsigned statement in which the agency clarified the terms of the I.R.S. protections.

Mr. Blanche’s announcement comes just days before the Senate Judiciary Committee is scheduled to vote to advance his nomination on Tuesday, and could potentially clear his path to be confirmed.

“My team and I have met with committee members and Senators over the past several weeks and addressed any concerns or outstanding questions,” Mr. Blanche wrote. “We have enjoyed good faith discussions, and as a result issue the following order and update.”