“Cautiously optimistic” is the buzz phrase on the Hill as GOP leaders, energized by late-breaking deals on energy and Medicare, are predicting that sine die will come before Thanksgiving.

“We’re still on target to adjourn” before Thanksgiving, said a spokeswoman for House Majority Whip Roy Blunt (R-Mo.), adding that leaders are very hopeful they can wrap up work by the weekend.

“All the gloom and doom predictions about being here until Christmas [last week] are not so,” said Jessica Boulanger, the Blunt spokeswoman.

But before they go, aides on both sides of the aisle and the Capitol acknowledge that plenty of work remains.

“There’s still a lot of work to do and it will involve some caffeine, but we can get through it,” said John Scofield, GOP spokesman for the House Appropriations Committee.

The adjournment strategy’s Achilles heel is legislation to provide a prescription drug component to Medicare and overhaul the Great Society-era program, Republicans and Democrats predict.

“It’s going to be close,” said Brendan Daly, spokesman for House Minority Leader Nancy Pelosi (D-Calif.). “We’re telling Members to be prepared to work though the week and as long as necessary” to finish, he said.

Republicans acknowledge that the Medicare conference report, which had not been released by press time last night, could throw the schedule off.

GOP aides were not willing to say what leaders would do if the Medicare bill does not pass, calling such talk “premature.”

“Mr. Blunt has said all along that the Medicare vote will be the toughest for Members,” Boulanger said. “We’re doing all we can to deliver that vote for the president.”

Senate GOP leaders will take their Conference’s temperature on the measure this morning during their regular Tuesday policy lunch, according to a GOP leadership aide.

But like his House counterparts, the aide believes once Senators see a final package they will coalesce around the deal brokered late Saturday night by the negotiating team that included two Democrats, Sens. John Breaux (La.) and Senate Finance ranking member Max Baucus (Mont.).

“I think once folks have the opportunity to review the legislation they will see that it is a critical piece of legislation and will want to vote for that,” said another senior Senate GOP aide.

House aides predict the Medicare bill will be the last vote in their chamber, possibly coming Saturday. In the Senate, however, some aides think the omnibus might be the last thing approved before adjournment.

Appropriators and leaders concede that an omnibus (some insiders are calling it a “minibus” because it will have about five spending bills) will be necessary to end the appropriations season. The Agriculture spending bill is the likely omnibus vehicle, according to Scofield.

Individual conference reports on foreign operations, Transportation-Treasury and energy and water should pass both chambers, leaving Agriculture, Commerce, Justice, State and the Judiciary, District of Columbia, Labor, Health and Human Services and Education, and Veterans Affairs, Housing and Urban Development for the omnibus, aides predict.

Senate Appropriations Chairman Ted Stevens (R-Alaska) has said he would like to bring up some unfinished spending bills individually as the Senate has not passed all 13 of its appropriations bills.

That could create a “logistical wrinkle,” according to Scofield, but he still believes the omnibus can be ready late this week.

If the Senate does finish a bill or two slated for the omnibus, it would be quickly sent to conference committee and that report would be rolled into the catchall package, according to one Senate GOP aide.