Washington ? Republicans blocked the Senate from beginning debate Monday on the Iraq war, a move that’s expected to delay but not prevent a vote on a nonbinding resolution opposing President Bush’s planned buildup of 21,500 troops.

The 49-47 procedural vote fell well short of the 60 votes that the Democrats needed to move to debate under Senate rules.

Senate Minority Leader Mitch McConnell, R-Ky., said Republicans were prepared to begin debate this week if Democrats agreed to allow debate on a proposal by Sen. Judd Gregg, R-N.H. His resolution takes no position on the troop buildup but rejects the notion of cutting off money for ground operations. “There’s not a single Republican senator seeking to avoid this debate,” McConnell said.

Democrats shot back that they’ll go beyond nonbinding resolutions against the troop buildup in the months ahead, including efforts to attach strings to war appropriations.

“You can run but you can’t hide,” said Senate Majority Leader Harry Reid, D-Nev. “They can maybe stop us temporarily from debating the escalation. They’re not going to stop us from debating Iraq.”

Democratic leaders had hoped to confine debate this week to two measures, one a bipartisan resolution to oppose the buildup led by Sens. John Warner, R-Va., and Armed Services Committee Chairman Carl Levin, D-Mich., the other a resolution by Sen. John McCain, R-Ariz., that supports the president.

Republicans say Democrats are afraid that many in their own caucus would sign on to Gregg’s plan. Such a vote might reveal Democrats’ divisions on the idea of cutting off money for troops. It also might be the only resolution that can pass, if the Warner-Levin plan falls short of the 60-vote threshold needed to avoid a filibuster.

Democrats accused Republicans of teaming with the White House to derail a debate that could embarrass the administration. They said the purpose of Gregg’s plan was to muddy the waters and predicted that Republicans would keep making additional demands if they won on this one.

“Iraq dominates our national life. It’s on the mind of tens of millions of Americans,” said Joseph Biden, D-Del., the Senate Foreign Relations Committee chairman. Not voting on what course to pursue “would be a total forfeiture of our responsibility,” he said.