WASHINGTON - Now that Osama bin Laden is dead, it is time to end the war in Afghanistan and bring U.S. troops home, several Republicans and Democrats in the House of Representatives demanded on Wednesday.

President Barack Obama will begin drawing down some of the 100,000 troops in Afghanistan in July, with all combat forces due out by 2014. That timetable is unacceptable to a growing number of war-weary U.S. lawmakers, who argue that the death of the al-Qaida leader is an opportunity for the United States to recalibrate its strategy.

"The successful mission that located and killed Osama bin Laden has raised many questions about the effectiveness of America's strategy to combat terrorism through a now 10-year-old nation-building effort in a deeply corrupt Afghanistan, especially in light of the serious fiscal challenges we face at home," Reps. Jason Chaffetz, a Republican, and Democrat Peter Welch wrote in a letter to colleagues on Wednesday.

They said it would be more effective to use "a targeted, worldwide counterterrorism strategy similar to the intelligence and special operations mission that located and killed bin Laden in Pakistan earlier this month."

Chaffetz and Welch planned to offer an amendment to the defence bill for withdrawing ground troops from Afghanistan. A group of eight Republicans and Democrats were pushing another measure to accelerate the transition from U.S. to Afghan control of operations.

While the amendments were unlikely to pass, the votes expected Thursday were certain to provide a measure of the congressional opposition to the war -- numbers that will not go unnoticed at the Pentagon and White House.

For a second day Wednesday, the House debated the broad, $690 billion defence blueprint that would provide a 1.6 per cent increase in military pay, fund an array of aircraft, ships and submarines, slightly increase health care fees for working-age retirees and meet the Pentagon's request for $119 billion to fight wars in Iraq and Afghanistan.

Still fuming over Obama's lack of extensive consultation with lawmakers before launching air strikes against Libya in March, the House adopted an amendment that says nothing in the bill could be construed as Congress authorizing the military operation in Libya.

"The president must firmly come to this Congress to seek authorization," said Republican Rep. Scott Garrett, sponsor of the amendment.

Separately, in testimony before the House Foreign Affairs Committee, three Republican lawmakers complained about Obama's decision not to follow the 1973 War Powers Resolution, which says the president can send troops into combat for only 60 days without congressional approval. That legal deadline for a full-blown authorization expired last Friday.

"Whatever the scope of the fight, our armed forces deserve, at the very least, a conversation between the president and Congress to explain why it is critical we send them into harm's way," said Rep. Tom Rooney, also a Republican.

Obama told Congress last week that he would welcome a resolution backing the limited U.S. involvement in the NATO-led military campaign.

By voice vote, the House adopted an amendment that would extend whistle-blower protection to members of the military who speak up about "ideologically based threats" by fellow service members that they believe could undermine U.S. security.

Rep. John Carter, R-Texas, sponsor of the measure, cited the shooting rampage at Fort Hood, Texas, and the accused shooter, Maj. Nidal Malik Hasan. A Pentagon review found Hasan's supervisors expressed concerns about his behaviour but failed to heed their own warnings.

Hasan is charged with 13 counts of premeditated murder and 32 counts of attempted premeditated murder in the November 2009 shooting spree on the Texas military post.

The House also voted to stop a White House effort to require anyone seeking government contracts to disclose political contributions. Obama's disclosure order, drafted in April, has not yet been issued, but reports about the order have upset Republicans and some Democrats.

"Government agencies should award contracts based on merit and value to taxpayers -- not politics," said Republican Rep. Tom Cole, the amendment's sponsor. The measure passed on a vote of 261-163.

House Republican leaders hope to finish the defence bill on Thursday, but first must plow through 152 amendments, several to eliminate disputed items in the bill that have drawn the threat of a presidential veto.

Provisions in the bill would limit Obama's authority to transfer terrorist suspects from the prison at Guantanamo Bay, Cuba, to foreign countries. The bill also bars transfer of detainees to facilities in the United States, even for trial.

The administration said the bill's provision "is a dangerous and unprecedented challenge to critical executive branch authority to determine when and where to prosecute detainees, based on the facts and the circumstances of each case and our national security interests."

The administration also opposes language in the bill revising the authorization to use military force established after the Sept. 11, 2001, terror attacks. Republican proponents say the provision mirrors what the Obama administration has spelled out as its justification for prosecuting various terrorist cases. Critics say it would give the president unlimited authority not only to detain terror suspects and prosecute them in military tribunals, but also to go to war.

"This authorization goes on forever," said Democratic Rep. John Garamendi. "We should never allow any president to have that unlimited opportunity to wage war."