An exasperated Sen. John Warner (R-Va.) put his colleagues on notice Wednesday that he would look to attach his resolution opposing President Bush’s plan to boost troop levels in Iraq to any measure moving across the Senate floor.

In a letter to Majority Leader Harry Reid (D-Nev.), Majority Whip Dick Durbin (D-Ill.), Minority Leader Mitch McConnell (R-Ky.) and Minority Whip Trent Lott (R-Miss.), Warner called the current stalemate “unacceptable” and said he would look to attach the resolution opposing Bush’s plan to any other measure considered by the Senate. He was joined on the letter by Republican Sens. Susan Collins (Maine), Gordon Smith (Ore.), George Voinovich (Ohio), Olympia Snowe (Maine) and Norm Coleman (Minn.).

Warner’s announcement followed a day of angry and increasingly partisan recriminations between Senate Democrats and Republicans over who was to blame for the collapse of a planned debate on Iraq.

Warner had joined McConnell, Lott and 44 other Republicans in filibustering his own resolution in an effort to pressure Reid into allowing a vote on a resolution sponsored by Sen. Judd Gregg (R-N.H.) that would put Members on record as opposing cutting funds for the war. Although Smith, Snowe and Voinovich also voted for the filibuster, Collins and Coleman, both up for re-election next year, did not.

But in their letter, the Senators warn that, “Monday’s procedural vote should not be interpreted as any lessening of our resolve to go forward advocating the concepts of [the Warner resolution. We will explore all of our options under the Senate procedures and practices to ensure a full and open debate on the Senate floor.”

Senate Republicans have privately expressed concern with McConnell’s handling of the Iraq situation thus far, worrying that continued public pressure from Democrats — who have successfully forced the GOP into appearing to defend Bush’s policies — could further erode support and end the filibuster.

Republicans also have said they are concerned that Democrats and their allies already have begun using the issue against incumbents up in 2008. MoveOn.org this week unveiled a new ad targeting Republican incumbents who voted for the filibuster, while the Democratic Senatorial Campaign Committee Wednesday circulated an e-mail criticizing Sen. John Sununu (R-N.H.) for backing the filibuster.

Sen. Charles Schumer (N.Y.), who serves as chairman of the DSCC and Democratic Caucus vice chairman, said Wednesday that despite suggestions to the contrary, Democrats are not motivated in this debate by electoral gains in 2008. But he did acknowledge that he believes his party is winning the debate, and that the war in Iraq will continue to dog vulnerable Republicans seeking re-election.

Erin P. Billings contributed to this report.