Updated 7:28 p.m.

President Obama was already facing a request from the House to justify the military campaign in Libya. On Tuesday, House Speaker John A. Boehner (R-Ohio) underscored the point, telling Obama that refusing to comply with the House’s request this week would “appear” to put him in violation of a 1973 law.

That law, the War Powers Resolution, says that presidents must notify Congress when an overseas operation begins--and obtain congressional authorization within 60 days. That deadline has already come and gone for the Libya operation, without Congress taking action.

By Sunday, 90 days will have elapsed. The resolution allows for a campaign lasting 90 days only in cases where “unavoidable military necessity respecting the safety of United States Armed Forces requires the continued use of such armed forces in the course of bringing about a prompt removal of such forces.”

In other words, where troops need another 30 days to carry out a fighting retreat.

But Boehner’s warning appears to have less to do with the legal deadline than with the expiration of the speaker’s own patience.

Boehner has sought to avoid a showdown with Obama over Libya, even as a motley bloc of conservatives and liberals in Congress have demanded one. Earlier this month, in fact, Boehner crafted a resolution that gave Obama 14 more days to make his case. Those 14 days run out on Friday.

Boehner’s proposal offered a less-confrontational alternative to another resolution, which flatly demanded the president pull troops out of the campaign.

On Tuesday, however, Boehner seemed to be telling Obama he would not — or could not — offer another extension after this week.

“The combination of [White House] actions has left many Members of Congress, as well as the American people, frustrated,” Boehner wrote in a letter to Obama, “by the lack of clarity over the Administration’s strategic policies, by a refusal to acknowledge and respect the role of the Congress, and by a refusal to comply with the basic tenets of the War Powers Resolution. ”

It was unclear, however, what Boehner would do if Obama did not comply with the House’s request.

Legally, his options might include a formal demand that troops be pulled out, or an attempt to cut off funding for the campaign. Politically, Boehner could seek to embarrass the president by turning the rhetorical focus of an energized, GOP-led House onto Obama’s decision-making in Libya.

White House spokesmen have said that Obama has acted in a manner consistent with the War Powers Resolution by holding regular briefings for members of Congress.

“We are in the final stages of preparing extensive information for the House and Senate that will address a whole host of issues about our ongoing efforts in Libya, including those raised in the House resolution as well as our legal analysis with regard to the War Powers Resolution,” National Security Council spokesman Tommy Vietor said Tuesday. “Since March 1st, administration witnesses have testified at over 10 hearings that included a substantial discussion of Libya and participated in over 30 member or staff briefings, and we will continue to consult with our congressional colleagues.”

Boehner said in his letter that it appeared the White House had actually settled on one of two conclusions — but not expressed either one in public.

“Either you have concluded the War Powers Resolution does not apply to the mission in Libya, or you have determined the War Powers Resolution is contrary to the Constitution,” Boehner wrote. “The House, and the American people whom we represent, deserve to know the determination you have made.”

The next flare-up of the Libya issue could come in the Senate, where a committee could take up a resolution on the Libya campaign on Thursday. A pair of Senators have already introduced a resolution that would allow the Senate to make the same demands on Obama as the House did earlier this month.