House Speaker John Boehner wrote to President Obama on Tuesday demanding to know on what grounds the president ordered the U.S. intervention in Libya.
Boehner's letter focused more on how Obama went about committing U.S. military assets in Libya and less on whether such military action was justified. He noted that under the War Powers Resolution, a president has 60 days to seek formal authorization from Congress after engaging in a conflict.
"Either you have concluded the War Powers Resolution does not apply to the mission in Libya," Boehner wrote the president, "or you have determined the War Powers Resolution is contrary to the Constitution."
He said the House and the American people deserve an answer. This weekend, it will be 90 days since the conflict in Libya began; that is the maximum number of days a military action can be sustained without congressional authorization under the War Powers Resolution. Boehner (R-OH) gave Obama until Friday to respond.
Earlier this month, the House voted to rebuke Obama for failing to pursue congressional approval and accused the president of not providing a "compelling rationale" for the Libyan operation. The House measure also required a report from the administration, due by Friday, on the scope of the Libyan operation, its costs and its impact on the wars in Iraq and Afghanistan.
"The ongoing, deeply divisive debate originated with a lack of genuine consultation prior to commencement of operations and has been further exacerbated by the lack of visibility and leadership from you and your administration," Boehner wrote.
The White House maintains that it has been in compliance with the War Powers Act and has called the resolutions unhelpful and unnecessary.
Initially the White House brushed off the nonbinding House measure, saying it had provided answers at various briefings. But last week it said it will respond to detailed questions on the U.S. mission in Libya within the deadline.
NATO commands the operation, but the United States still plays a significant support role that includes aerial refueling of warplanes and intelligence, surveillance and reconnaissance work.
In the Senate, the fate of a resolution signaling support for the operation was in limbo.
Sen. John Kerry (D-MA), chairman of the Foreign Relations Committee, said plans for the panel to meet Thursday and write a resolution would be delayed to allow lawmakers to review the White House report. He left open the possibility of action on a resolution next week.
"We just want everybody to see the information and see how it impacts their thinking," Kerry said.
Among the backers of the resolution is Republican Sen. John McCain of Arizona, a leading proponent of military action against Moammar Gadhafi, the top Republican on the Armed Services Committee and Obama's presidential rival in the 2008 election. McCain warned his GOP colleagues against any steps that would send a positive signal to Gadhafi.
"I caution my friends, both here in the Senate and in the House of Representatives, that we don't want to do anything or pass legislation which would encourage Gadhafi to remain in power," McCain told reporters.
Sens. Jim Webb (D-VA) and Bob Corker (R-TN) introduced a separate resolution last week that presses Obama to seek congressional consent for continued U.S. military involvement in Libya and requires the administration to provide a detailed justification for the decision to go to war.
On Monday, the House essentially voted to prohibit money for the Libya operation, backing an amendment barring the use of any funds in contravention of the War Powers Act. The vote was 248-163 on a spending bill that still must be reconciled with the Senate.
One of the most vocal critics of Obama, antiwar Rep. Dennis Kucinich (D-OH), said he and Rep. Walter Jones (R-NC) will file a complaint in federal court Wednesday over the Libyan war.
NPR's David Welna contributed to this report, which includes material from The Associated Press