President Barack Obama faced a withering but symbolic congressional rebuke over Libya on Friday, with even White House allies due to back a measure aimed at sharply curbing US operations there. Defying a last-ditch appeal from US Secretary of State Hillary Clinton and a warning from NATO, the House of Representatives was expected to approve a resolution meant to end US strikes on Libyan strongman Moamer Kadhafi\'s forces. The measure\'s supporters, Republicans and Democrats alike, have expressed anger that Obama did not seek formal authorization from Congress for use of the US military within the 60-day window provided by the 1973 War Powers Act. With the conflict near the 100-day mark, lawmakers angrily condemned Obama for ignoring that law and stressed that the US Constitution reserves to Congress the right to declare war, though it makes him the military\'s commander in chief. \"The president is becoming an absolute monarch, and we must put a stop to that right now if we don\'t want to become an empire instead of a republic,\" said Democratic Representative Jerrold Nadler as debate opened. Presidents of both parties have ignored the 1973 law, but lawmakers faced a deeply war-weary US public frustrated with a decade of overseas conflicts in Afghanistan in Iraq. The new measure, which was expected to die in the Senate, aimed to cut off funding except for tasks in support of NATO, like aerial refueling, intelligence, surveillance, reconnaissance, planning, or search and rescue. \"I don\'t want to do anything that would undermine NATO or to send a signal to our allies around the world that we are not going to be engaged,\" Republican House Speaker John Boehner told reporters on Thursday. Lawmakers were first expected to vote down a resolution authorizing the US military role, including drone strikes and bombings, for one year. \"Yes, the president should have come to us early, should have come to us at the very beginning, and allowed Congress to carry out its constitutional obligations,\" said Democratic Representative John Garamendi. But US forces are acting under a UN mandate \"to defend and protect\" Libyan civilians, and as lawmakers \"we need to provide the president with the necessary powers to carry out that obligation in a very limited period of time,\" he added. The debate came as NATO Secretary General Anders Fogh Rasmussen told the French newspaper Le Figaro that a US Congress vote to pare back funding \"would of course be damaging to the Libyan operation.\" \"But I am confident. American lawmakers will take their global responsibility seriously,\" he said in an interview published on the French daily\'s website. The United States joined Britain and France in attacking Kadhafi\'s forces on March 19 in a UN-authorised mission to protect civilians as the regime attempted to crush an uprising. The United States withdrew into a supporting role when NATO took command of the mission on March 31, but the US military still provides the brunt of air-to-air refueling planes and surveillance aircraft that are critical to the mission, and carries out drone attacks and air strikes. In a last-ditch bid to enlist support for the conflict, Clinton met behind closed doors with House Democrats on Thursday to urge them not to tie the administration\'s hands. \"I, myself, believe the president has the latitude to do what he is doing as long as there are no boots on the ground,\" Democratic House Minority Leader Nancy Pelosi told reporters. But \"I also always say that consultation strengthens the resolve of our country, and the more consultation the better,\" she added.