Citing “important US interests,” the White House on Wednesday claimed constitutional authority for ongoing US military operations in Libya, now estimated to cost US taxpayers $1.1 billion through Sept. 30.

The claim was made in a report released as lawmakers converged on the White House for an annual picnic. It is the Obama administration’s response to a House resolution on June 3 calling for the release of documents providing a legal justification for the president’s decision to commit US forces without authorization from Congress.

Stepping up the pressure on President Obama, Speaker John Boehner (R) of Ohio on Tuesday warned that the president will be in violation of the War Powers Act if he does not obtain congressional approval by Sunday.

Just hours before release of the White House documents, 10 House members, led by Reps. Dennis Kucinich (D) of Ohio and Walter Jones (R) of North Carolina, filed suit in a federal court challenging the legality of US operations in Libya.

“Where in the world is Congress when an administration decides we want to bomb a country? For goodness sake, there’s a Constitution!” says Congressman Jones, in a phone interview.

“I think those who drafted the Constitution would probably be standing with us today and applaud the action we’re taking,” he adds.

The White House justification for the use of force in Libya without congressional authorization came down to three key points:

• US forces are playing a “constrained and supporting role” in a multinational coalition. “At no point did the US act alone.”

• The operations of that coalition are “legitimated by and limited to the terms of a United Nations Security Council Resolution.”

• If the US military were to cease its participation in the NATO operation, “it would seriously degrade the coalition’s ability” to protect civilians and to enforce a no-fly zone and an arms embargo.

“The United States is providing unique assets and capabilities that other NATO and coalition nations either do not posses or possess in very limited numbers,” the report concluded.

Early responses from House GOP leaders signal that that explanation did not satisfy congressional concerns.

'Creative arguments' by White House

“The creative arguments made by the White House raise a number of questions that must be further explored,” said Brendan Buck, a spokesman for Speaker Boehner.

“We will review the information that was provided today, but hope and expect that this will serve as the beginning, not the end, of the president’s explanation for continued American operations in Libya,” he added.

Rep. Scott Garrett (R) of New Jersey, who chairs the Constitutional Caucus, said that Wednesday’s “progress report from the White House is no substitute for congressional authorization.”

“If the president thinks it’s in the best interest of the United States to commit US military personnel to the conflict in Libya, he needs to come to Congress for an up or down vote. Otherwise, he is in violation of [the] Constitution and the oath he took to preserve, protect and defend it,” he added, in a statement released after the report.

To date, the US operation in Libya has cost $713.6 million, including $1.1 million for humanitarian operations. There has not been a significant operational impact on US military or diplomatic activities in Iraq and Afghanistan, the report said.

The classified annex of the report included an assessment of opposition military groups and extremist groups in Libya – a main concern of congressional critics. The unclassified version of the report briefly described the Libyan opposition’s 45-member Transitional National Council as representing the Libyan people during the current crisis.

“We are encouraged by the steps taken by the TNC to bring Libyans together to plan their own future and a permanent, inclusive constitutional system that will protect the rights of all Libyans,” the report said. “We are not aware of any direct relationship between the TNC and al-Qaeda, Hezbollah, the Libya Islamic Fighting Group or any other terrorist organization.”

UN authorization challenged

A former adviser to Congress on executive power issues challenged the president’s claim to engage US forces with authorization from the United Nations. “It’s absurd to say that the president can get authorization from the UN Security Council and not the Congress,” said Louis Fisher, scholar in residence with the Constitution Project who worked for the Congress on such issues from 1970 to 2010.

“The President and the Senate cannot take power from Congress, including the House of Representatives, and give it to an outside body. If anyone thought that the UN Charter was going to do that, it never would have passed,” he added.

Meanwhile, the Senate Foreign Relations Committee this week delayed a bipartisan resolution expressing support for a limited intervention in Libya in order to give senators time to consider the new White House report. The resolution is sponsored by committee chairman John Kerry (D) of Massachusetts and Sen. John McCain of Arizona, the top Republican on the Senate Armed Services Committee.

In its report, the White House said that it had “repeatedly indicated its strong support” for this resolution, “that would confirm that both branches are united in their commitment to supporting the aspirations of the Libyan people for political reform and self-government.”