Deliberations are also continuing over a reduction to the top individual tax rate. A White House official said that Mr. Trump had not yet signed off on a proposal to lower the rate to 35 percent from 39.6 percent. Mr. Trump has said that the rich will not see their tax bill shrink.

The Republican plan is expected to call for creating a 25 percent tax for “pass through” businesses. Pass-throughs, which currently can include small businesses, farms and other types of partnerships, account for a vast majority of business income and their profits are taxed at individual income rates.

The framework is also expected to propose a shift to a territorial tax system, in which overseas earnings of American companies are not taxed in the United States. However, sorting out such a shift and potential measures to prevent erosion of the tax base — like a controversial global minimum tax — are likely to be left to Congress.

Mr. Brady would not reveal how much, if any, detail on paying for the plan would be made public this week. Under Senate rules, if the legislation adds to the deficit after a period of 10 years, some of the tax cuts could expire.

“We continue to be focused on permanency or as much of it as we can achieve,” he said.

The framework is expected to be a starting point in a race to get a tax bill passed by the end of the year. Mr. Brady said that more detailed legislative language would be produced after Congress passes a budget resolution that includes a tool, known as reconciliation instructions, allowing a tax bill to pass the Senate with a simple majority.

Republican leaders maintain that it is possible to swiftly pass the tax overhaul. But the hard part is about to begin.

Legions of lobbyists who have spent their careers quietly roving around Washington, pushing to preserve beneficial tax structures, are ready to pounce.