By Susan Cornwell
WASHINGTON (Reuters) - The chasm between lawmakers and the White House over the U.S. role in Libya appeared to deepen on Thursday as House Speaker John Boehner warned that an unhappy Congress could vote to cut off war funds.
With criticism building of the military intervention and the Obama administration's refusal to ask Congress for its consent, Boehner said the White House must better clarify the legal basis for the mission by Friday or lawmakers could take action next week.
"The House has options, we're looking at those options ... Congress has the power of the purse, and certainly that is an option as well," Boehner said.
Boehner's remarks came a day after the White House sent lawmakers a 32-page letter defending President Barack Obama's policy, while saying the Libyan conflict was too limited to require congressional authorization under the 1973 War Powers Resolution.
Another key Republican, Senator John McCain, while criticizing Obama's handling of the issue, warned war critics to stop and think before upending U.S. Libya policy and, as McCain put it, riding to the rescue of "the mad dog of the Middle East," Muammar Gaddafi.
McCain, the Republican presidential nominee in 2008, said he and Democratic Senator John Kerry would introduce a measure authorizing the limited use of force in Libya, to try to head off what McCain called a "wholesale revolt" in Congress against Obama administration policy.
McCain blamed the lawmakers' revolt largely on the White House. He said it was the result of "delay, confusion, and obfuscation" by the president about what the Libya mission was, as well as a refusal to seek congressional authorization for the war.
Criticism in Congress of the Libyan conflict has been fueled by general unease in both parties over a third war after Iraq and Afghanistan, and worries about more military spending in a time of massive debt.
There is also an element of partisan criticism of a Democratic president from Republican lawmakers, including some like Representatives Michele Bachmann and Ron Paul who are seeking their party's nomination for president.
NATO is leading the effort to protect Libyan civilians from Gaddafi's forces -- a mission whose unstated goal seems to be to drive the Libyan leader from power -- with the U.S. providing logistical support and intelligence.
Boehner said the White House letter didn't make clear whether Obama's legal advisers agreed with the president's interpretation. He said he wanted an answer to that question by Friday.
"It doesn't pass the straight face test in my view that we are not in the midst of hostilities," Boehner said. The U.S. had launched drone strikes and was part of efforts to bomb Muammar Gaddafi's compound, he said. "We're spending $10 million dollars a day."
The U.S. Constitution says that Congress declares war, while the president is commander in chief of the armed forces.
The 1973 War Powers Resolution tried to resolve the tensions in these roles by prohibiting U.S. armed forces from being involved in military actions for over 60 days, with a 30-day pullout period. Boehner says the 90 days are up Sunday.
In the Senate, McCain, a former Navy pilot, agreed that the White House argument was puzzling, and said Obama should have asked for Congress' blessing for U.S. actions in Libya. But he urged fellow Republicans not to oppose the war "simply because a leader of the opposite party occupies the White House."
"I believe the president did the right thing by intervening to stop a looming humanitarian disaster in Libya," McCain said, adding that "we are succeeding."
Republicans are not the only ones who feel Obama has not shown enough concern for the opinion of Congress on the war. "He (Obama) made a great mistake in not asking permission; for support," said Representative Barney Frank.
Frank added, however, that if Obama did ask for consent, he would vote no. "I think this thug should be removed, but not by Americans. I think this is a time for Europeans to do it."
The White House letter said the U.S. role had cost $716 million as of June 3 and would reach $1.1 billion by September 30.
(Additional reporting by Richard Cowan)