Updated: 8 p.m.

The partisan warfare that has characterized the lame-duck session enveloped the Senate’s debate over the new Strategic Arms Reduction Treaty on Wednesday, with Republicans vowing to block ratification and Democrats countering that the GOP has negotiated in bad faith.

Senate Minority Whip Jon Kyl (Ariz.), the lead Republican negotiator on START, told reporters that he was determined to kick consideration of the treaty to next year and acknowledged that he was actively rounding up the votes to sink ratification.

Foreign Relations Chairman John Kerry, the chief Senate negotiator on behalf of the White House, charged Kyl with stalling and said the chamber would remain in session through the holidays if necessary to ratify START.

“We believe we should stay here as long as it takes to get this treaty ratified, and we are prepared to do so,” the Massachusetts Democrat, flanked by Armed Services Chairman Carl Levin (D-Mich.) and Select Intelligence Chairman Dianne Feinstein (D-Calif.), told reporters during a Capitol news conference. “I think we’ve reached over every way possible to be fair and to allow people an opportunity to comment on this treaty.”

Kyl countered that Democrats were attempting to jam down START in the waning days of the lame duck, and he promised that Republicans would resist. Key GOP Senators who support START on its merits said they would withhold their backing if Democrats proceed with “rushing” consideration of the treaty even as the Senate is engaged in a contentious debate over a $1.1 trillion omnibus spending bill and other legislation.

“The most important issue facing our country right now is to ensure that people’s taxes don’t increase and that the government can be funded at a reasonable cost into next year. Those two items of business ought to be included before we do anything else,” said Kyl, who was joined by about a dozen of his GOP colleagues at a news conference immediately following the successful vote to open debate on START. “The process that we’ve embarked upon here is an inappropriate process.”

The Senate voted 66-32 on Wednesday afternoon to proceed to the debate on START, which President Barack Obama signed this year with Russia. According to Senate rules, only 51 votes are required to open debate on treaties, but 67 are needed for ratification. As of Wednesday evening, there was no agreement between Majority Leader Harry Reid (D-Nev.) and Minority Leader Mitch McConnell (R-Ky.) on debate time and amendments.

Sen. Jim DeMint had planned to force the text of START to be read aloud in the chamber before the formal floor debate could commence, a process that could have consumed up to 15 hours of Senate floor time. However, the South Carolina Republican stood down after Reid and McConnell reached an agreement to delay the beginning of the START debate until Thursday and use what was left of Wednesday for general debate and floor time.

That bit of bipartisan comity could be short-lived. At least three Republicans who voted with the Democrats to open the debate on START said that if they believe the majority is not providing adequate floor time for its consideration, they would oppose the treaty upon final passage out of respect for Kyl and other GOP colleagues who oppose ratification during the lame duck.

The three Republicans are Armed Services ranking member John McCain (Ariz.) and Sen. Lindsey Graham (S.C.), who are opposed to the bill but have indicated they might be close to resolving their differences with the Obama administration, and Sen. Scott Brown (Mass.), who is reserving judgment pending amendments.

Republican Conference Chairman Lamar Alexander (Tenn.) and Sen. Judd Gregg (R-N.H.), who have already announced their support for START, also said they would oppose the treaty absent insufficient debate time.

“I believe that Jon Kyl has the right to have — he’s a very substantive guy around here — he has a right to have his case made in an orderly way on the floor and not in the middle of the Christmas season,” Gregg said.

Foreign Relations ranking member Dick Lugar (Ind.) is the notable exception to the GOP opposition.

Senate Republicans led by Kyl have been pushing for several months for the START debate to be delayed until 2011, a desire that gained steam after the Nov. 2 elections, when the GOP picked up six seats and expanded its Conference from 41 to 47 Members in the 112th Congress. The Republicans’ main substantive concerns with the treaty include its potential effect on U.S. missile defense capabilities.

The GOP has also sought to secure money for the modernization of existing nuclear weapons stockpiles as a part of the START negotiations. Republicans also complain that the lame-duck session offers inadequate time to debate the treaty.

Democrats dismiss the Republicans’ concerns as a smoke screen for seeking to run out the clock on the 111th Congress, which expires Jan. 4, and kill START altogether. Ratification of the treaty is Obama’s No. 1 foreign policy priority.

During their news conference, Feinstein, Kerry and Levin charged that the Republicans have had more than a year to study the treaty. They contend that Democrats have bent over backward to satisfy the GOP opposition, accepting several requested changes to the treaty’s language and agreeing to delay the debate until late in the year to satisfy requests for more time to review it.

“We’re not going to be thwarted by the obstructionists,” Levin said.

Feinstein added, “We should unify this treaty without delay.”

Republicans responded by angrily charging Reid with “incompetence” in his management of the Senate, likening the process to the end-of-year debate and Christmas Eve passage of the health care reform bill last year. Many of the Republicans who joined Kyl at the news conference Wednesday said they are inclined to ultimately support ratification of START, but not during the lame duck.

The Republicans who went before the cameras to protest included Alexander and Sens. John Barrasso (Wyo.), Kit Bond (Mo.), Saxby Chambliss (Ga.), Orrin Hatch (Utah), Mike Johanns (Neb.), Mark Kirk (Ill.), George LeMieux (Fla.), James Risch (Idaho), Pat Roberts (Kan.) and John Thune (S.D.).

“I feel like I’m being jammed,” Johanns said.