NEW YORK President Barack Obama overruled legal advice from top administration lawyers, siding with other advisers who said he had legal authority to continue air strikes against Libya without congressional approval, the New York Times reported on Saturday. The White House insists the president did not need congressional approval to authorise US support for Nato's mission, because the military campaign is limited in scope. Critics argue the action violates a Vietnam War-era law limiting military action without congressional approval to 60 days. Citing officials familiar with the administration's deliberations, the Times' report said Pentagon General Counsel Jeh Johnson and acting head of the justice department's Office of Legal Counsel Caroline Krass had advised Obama that the US involvement in the Libya air campaign constituted "hostilities". But the US president opted to follow the advice of White House counsel Robert Bauer and state department legal adviser Harold Koh, who argued the US involvement fell short of "hostilities", the paper said. US presidents can override the legal conclusions of the Office of Legal Counsel, but it is very rare for that to happen, it said. Members of Congress have accused Obama of violating that law since 20 May, when the 60-day deadline ended. Sunday marks 90 days since the US joined the Nato-led no-fly zone mission over Libya . In a 32-page document delivered to Congress this week, the White House said that US forces involved in the NATO campaign were merely playing a supporting role. That role, it said, did not match the definition of "hostilities" as described under the War Powers Resolution of 1973. "US military operations are distinct from the kind of 'hostilities' contemplated by the resolution's 60-day termination provision," it said. AFP add: US lawmakers from the right and left on Saturday stepped up criticism of President Barack Obama over his Libya intervention after a report that he had overruled top government lawyers. The New York Times reported Friday that Obama had rejected the opinions of top lawyers at the Pentagon and Justice Department who said the United States was engaged in "hostilities" in Libya requiring congressional approval. The White House has argued that because US forces are playing a supporting role in the NATO air campaign and because no ground troops are involved it does not need legislative backing under the 1973 War Powers Resolution. Republican Bob Corker, a member of the Senate Foreign Relations Committee, took aim at Obama over the Times report, accusing him of ignoring the Justice Department's opinion because it didn't fit his "agenda." "If dropping bombs and firing missiles on military installations are not hostilities, I don't know what is. The president's actions on Libya are nothing short of bizarre," he said in a statement. "The president would likely have received overwhelming support for the operations in Libya , but his approach has needlessly burned through goodwill with Congress and violated the trust of the American people." Corker is the co-author, with Democratic Senator Jim Webb, of a resolution seeking an explanation for the US Libya mission, prohibiting the introduction of US ground forces and calling on Obama to seek congressional authorization. Far left Democratic congressman Dennis Kucinich - a staunch opponent of the US intervention - said it was "very disturbing" that Obama was proceeding without congressional authorization despite the lawyers' advice. "An immediate remedy to this fiasco is needed. Congress must move swiftly to cut off funds for the operation," Kucinich said, adding that the situation had the "makings of a Constitutional crisis." Meanwhile, the Libyan government dismissed rebel denials that the two sides have been holding talks and hit out at NATO's air war as Moamer Gaddafi defiantly vowed the alliance was doomed to defeat. Addressing a news conference in Tripoli late on Friday, just hours after loud explosions again rocked Tripoli, Prime Minister Baghdadi al-Mahmudi accused NATO of committing "war crimes and crimes against humanity" by "directly targeting civilian sites" with air raids over the past three days. State television aired Gaddafi's comments in what it said was a live telephone call from the Libyan leader, who has gone underground since the Western-led air war was launched in March, as thousands of his supporters gathered in Tripoli's Green Square for their biggest rally in weeks. Baghdadi said that the governments of the countries where regime envoys had approached rebel representatives were fully aware that multiple contacts were under way as detailed by Russian envoy Mikhail Margelov. "Ask the Egyptians, French, Norwegians and Tunisians for information. They will tell you the truth," Baghdadi said.