WASHINGTON — President Trump will propose a sweeping rewrite of the federal tax code on Wednesday, outlining a plan to reduce rates for corporations and individuals and eliminate some popular deductions, in a move that will set off a scramble among powerful groups eager to protect their tax breaks.

The proposal will call for slashing the corporate tax rate to 20 percent from 35 percent, doubling the standard deduction for individual taxpayers and slightly increasing the bottom tax rate to 12 percent from 10 percent, according to two officials briefed on the details of the blueprint.

The framework, which has been agreed upon by Republican leaders in the House and Senate, leaves most of the details to Congress but proposes a reduction in the individual rate to 35 percent from 39.6 percent, while leaving the door open for an unspecified, higher bracket for the wealthiest Americans. The plan would also, for the first time, create a 25 percent tax for “pass through” businesses, which account for the vast majority of business income in the United States and are currently taxed at individual rates.

Pulling the tax code levers inevitably creates winners and losers, but the scant details of the plan, including how it will be paid for and which deductions are on the chopping block, make it impossible to determine the distributional effects and whether it would actually help middle-class taxpayers and not the wealthiest Americans.