WASHINGTON: President Barack Obama faces mounting pressure from lawmakers who have accused him of steamrolling Congress by joining the NATO air war in Libya and are threatening to cut off funding for US operations. The dispute touches on the separation of powers, a bedrock principle of US democracy, and has grown more heated following a report that Obama overruled top Defense and Justice Department lawyers in choosing to bypass Congress. The New York Times reported Friday that Obama had rejected the opinion of the government lawyers, who said the United States was engaged in “hostilities” in Libya that required congressional approval. The White House has argued that because US forces are playing a supporting role in the NATO air campaign, and because no US ground troops are involved, it does not need legislative backing under the War Powers Resolution. The 1973 law seeks to limit the executive branch's power to use military force abroad, and says that, after 60 days, the president must seek approval from Congress or else withdraw troops within 30 days. The US and Western allies launched the bombing campaign in Libya on March 19 to protect civilians from his brutal crackdown on a pro-democracy uprising. Obama faces his toughest critics in the House of Representatives, where Republican House Speaker John Boehner has threatened to cut off funding for the three-month-old bombing campaign. “The War Powers Resolution is the law of the land and cannot simply be ignored. The White House's suggestion that there are no ‘hostilities' taking place in Libya defies rational thought,” Boehner said in a statement Friday. Top US senators from both parties have, meanwhile, sought a way out of the impasse, proposing a resolution that would authorize the war but require a more detailed justification and a promise that no ground troops will be used. “Whether people like it or not, we are engaged in Libya, and we are succeeding,” Republican Senator John McCain, who co-authored the proposal with Democratic Senator John Kerry, said Thursday. – Agence France