Legislation banning torture of detainees in U.S. custody was sidetracked on Saturday when House of Representatives Republicans insisted on adding an unrelated amendment on campaign financing.

But the requirement for humane treatment of prisoners — pushed by Arizona Republican Sen. John McCain and reluctantly accepted by President George W. Bush — also was likely to be included on a separate defense spending bill that Congress was poised to act on in the next day or two.

However that bill to fund the Pentagon was not finalized and it faced a number of hurdles before being signed into law.

In Congress’ last-minute scramble to push through legislation before adjourning for the year, House Republican leaders insisted on adding to a defense policy bill with the McCain amendment an unrelated measure that would impose new regulations on political spending by advocacy groups.

Senate Armed Services Committee Chairman John Warner, a Virginia Republican, and Michigan Democrat Carl Levin, the committee’s top Democrat, refused to accept the add-on measure, stalling the defense policy bill that the House had been set to clear on Saturday and the Senate shortly after that.

House Republicans showed little sign of giving up on the campaign finance measure, even if it derailed the defense policy bill. “We may not be able to get that done today or tomorrow or this year,” Acting House Majority Leader Roy Blunt of Missouri said of the legislation.

Rep. Ike Skelton of Missouri, top House Armed Services Committee Democrat, lashed out at House Republican leaders.

“We have young men and women in uniform all over this world — Afghanistan, Iraq — and yet we can’t get the bill here that authorizes a pay raise … all the ammunition that they need, the medical care they need, the policies set forth in the detainee language,” Skelton complained.

McCain’ amendment requiring humane treatment of detainees and setting standards for interrogations has followed a tumultuous course, pitting the Republican-led Congress, which gave the measure broad bipartisan support, against Bush.

Bush, who said the amendment would hamper intelligence-gathering in the U.S. war on terrorism, relented on Thursday and gave it a public endorsement at a White House meeting with McCain and Warner.

The administration has been hammered by scandal over the sexual and physical abuse of detainees by U.S. soldiers at Abu Ghraib prison in Iraq, reports the CIA has run secret prisons abroad to hold terrorism suspects, and harsh interrogations at U.S. facilities at Guantanamo Bay, Cuba.

While bowing on the McCain amendment, the White House gained some leeway on treatment of detainees in another amendment that would bar detainees at Guantanamo from challenging their detention in federal courts and allow evidence obtained by coercion to be used against them.

That amendment, sponsored by South Carolina Republican Sen. Lindsey Graham, was included in the defense policy bill that has been stalled, but not in the Pentagon funding bill.