The new authorization to use military force against Al Qaeda was unveiled by the committee chairman, Representative Howard P. McKeon, Republican of California. The committee is scheduled to vote Wednesday on amendments to the bill.

The provision states that Congress “affirms” that “the United States is engaged in an armed conflict with Al Qaeda, the Taliban, and associated forces,” and that the president is authorized to use military force — including detention without trial — of members and substantial supporters of those forces.

That language, which would codify into federal law a definition of the enemy that the Obama administration has adopted in defending against lawsuits filed by Guantánamo Bay detainees, would supplant the existing military force authorization that Congress passed overwhelmingly on Sept. 14, 2001. It instead named the enemy as the perpetrators of the Sept. 11 attacks.

Critics of Mr. McKeon’s provision have reacted with alarm to what they see as an effort to entrench in a federal statute unambiguous authority for the executive branch to wage war against terrorists who are deemed associates of Al Qaeda but who lack a clear tie to the Sept. 11 attacks.

In a joint letter to Congress, about two dozen groups — including the American Civil Liberties Union and the Center for Constitutional Rights — contended that the proposal amounted to an open-ended grant of authority to the executive branch, legitimizing an unending war from Yemen to Somalia and beyond.

“This monumental legislation — with a large-scale and practically irrevocable delegation of war power from Congress to the president — could commit the United States to a worldwide war without clear enemies, without any geographical boundaries” and “without any boundary relating to time or specific objective to be achieved,” the letter warned.