President Bush is sending his top aide on national security affairs to Capitol Hill on Thursday to confront what has become a tough crowd on the Iraq war.

A majority of senators believe troops should start coming home within the next few months. A new House investigation concluded this week that the Iraqis have little control over an ailing security force. And House Republicans are calling to revive the independent Iraq Study Group to give the nation options.

While the White House thought they had until September to deal with political fallout on the unpopular war, officials may have forgotten another critical date: the upcoming 2008 elections.

"This is an important moment if we are still to have a bipartisan policy to deal with Iraq," Sen. Richard Lugar, R-Ind., said in an interview Wednesday.

If Congress and the White House wait until September to change course in Iraq, Lugar said "It'll be further advanced in the election cycle. It makes it more difficult for people to cooperate. ... If you ask if I have some anxiety about 2008, I do."

Lugar, the senior Republican on the Senate Foreign Relations Committee, plans to meet Thursday privately with Bush's national security adviser, Stephen Hadley. Hadley requested the meeting after Lugar delivered a lengthy floor speech contending the president's war strategy won't have time to work and that U.S. troops should start leaving.

National Security Council spokesman Gordon Johndroe said Hadley's message Thursday on Capitol Hill will be "where we see things currently in Iraq and that we need to see what the commanders on the ground and the ambassador have to say in September."

White House spokesman Tony Snow said he sees little space between Lugar and the president, who Snow said sees troop withdrawals "over the horizon."

"We think it's important to allow the Baghdad security plan to work," Snow told reporters. "But if you take a look at what Sen. Lugar's trying to figure out, it's what configuration is going to be conducive in the long run to success and also building greater bipartisan support."

Indeed, the senator says he still opposes Democratic proposals setting an end date on the war. Lugar also warns against withdrawing forces too quickly and putting troops in harms' way.

But Lugar's contention that the military begin now a "sizable" drawdown of U.S. forces aligns Lugar more with Democrats than Bush and poses a serious challenge to the administration's insistence that it manage the war on its own timetable. As a prominent voice in the GOP caucus, Lugar says he would consider legislative measures this summer if the White House is unresponsive to his position.

Other GOP senators have aligned themselves with a similar position, including Sen. George Voinovich. On Tuesday, the Ohio Republican sent Bush a letter calling for "responsible military disengagement" from Iraq.

Republican Sens. Norm Coleman of Minnesota and John Sununu of New Hampshire also say they want to see troops departing Iraq by early 2008. Sen. Susan Collins, R-Maine, said Wednesday she is working with Sens. John Warner, R-Va., and Ben Nelson, D-Neb., on a new bipartisan policy for Iraq.

In another challenge to Bush's Iraq policy, House Republicans urged the White House on Wednesday to revive the Iraq Study Group. A blue-ribbon panel chaired by Republican James Baker and Democrat Lee Hamilton, the group concluded last December that U.S. troops could leave by March 2008 if certain steps were taken.

Last week, the House voted 355-69 to appropriate a $1 million budget for another study, though the bill is unlikely to become law for a few weeks. Reps. Chris Shays, R-Conn., and Frank Wolf, R-Va., said they hope the administration will move ahead on its own to reconvene the group.

"If you had a health care problem, you'd want to get a second opinion quickly," Wolf told reporters.

The Republican push comes as a new bipartisan investigation found that Iraqi ministries are incapable of "accounting for, supporting or fully controlling their forces in the field." The report also confirmed that the U.S. is shifting its focus from trying to transfer control to Iraqi troops — because they are not ready — to trying to secure neighborhoods.

The findings, detailed in a 205-page report, cast doubt on how soon U.S. troops could leave Iraq under Bush's plan to "stand down" coalition forces as Iraqi troops "stand up."

"Basically, the department can tell us how many people they've trained and how many weapons they're given, but they can't tell us enough about how well they can perform their missions or even plan them," said Rep. Marty Meehan, D-Mass., the outgoing chairman of the House Armed Services oversight and investigations subcommittee.