Majority Leader Harry Reid confidently predicted that Bush will not use his constitutional authority to fill top jobs without Senate confirmation. “We have an agreement with the president,” said Reid, D-Nev. “We don’t think there will be any.”

Privately, a leadership aide said amicable negotiations are under way, but a series of pro forma sessions during August remains a possibility.

A White House spokeswoman said Reid was wrong. “We do not have an agreement,” said Emily Lawrimore. “We don’t ever comment on the potential for recess appointments.”

Jim Manley, a Reid spokesman, said Democrats have worked with Republicans to clear nominees this week to high-level posts at the Treasury, Energy and Education departments, as well as two ambassadors, 56 generals and five admirals. Committees are working to clear other non-controversial nominees.

“In view of this work and our view that the process is working well, the issue of recesses should be moot,” Manley said. “If, despite this work, we see that the president still plans to recess [appoint] controversial nominees, Sen. Reid may need to keep the Senate in pro forma session during the August break.”

Rather than having the Senate adopt a month-long adjournment resolution, Reid could opt for a recess of a few days. Then, Democratic senators — most likely from Maryland, Virginia or another nearby state — would be asked to take turns convening the Senate briefly every few days.

With two senators’ “holds” preventing Senate action on the nomination of former Rep. Jim Nussle to be White House budget director, the Iowan could be a top prospect for a recess appointment.

And Bush has yet to nominate a successor to Jim Nicholson, who resigned this month as Veterans Affairs secretary.

A Republican aide said John Rood, nominated to be undersecretary of State for arms control, and Henrietta Fore, nominated as administrator of the U.S. Agency for International Development, also could be installed during August.

The Rood and Fore nominations are under the jurisdiction of the Foreign Relations Committee, where Chairman Joseph R. Biden Jr., D-Del., almost dared the White House to cross him.

“There will be no recess appointments on my committee or they will not get another single nominee for anything at all from the Committee on Foreign Relations,” Biden declared. “I made that clear to the secretary of State. Absolutely, positively clear. Not a one. Mark me down. Not a one.”

Minority Whip Trent Lott, R-Miss., said he expects Reid and Bush to reach an agreement. “I assume there are recess appointments that can and should be made,” Lott said. “In the case of Sen. Biden and these foreign relations or ambassadorial or State Department appointments, it is irresponsible not to confirm those people.”

The Constitution allows presidents to fill vacancies “that may happen during the recess of the Senate” without waiting for confirmation votes.

The legal ground is unsteady, with disputes focusing on the word “happen.” That could be interpreted as vacancies that occur during a recess, but court and attorney general opinions have construed the phrase to include vacancies that exist before a recess begins.

The Supreme Court has declined to clarify the issue.

A benchmark in the debate was a 1921 opinion by Attorney General Harry M. Daugherty. He viewed recess appointments constitutional during a 29-day recess, but said “an adjournment for five or even 10 days [cannot] be said to constitute the recess intended by the Constitution,” according to a Congressional Research Service report.

More recently, a Justice Department brief in 1993 implied that the president could make appointments during recesses of more than three days.

Recess appointees can serve until the end of the following session of Congress. A recess appointee this year could thus serve until the closing days of Bush’s term in office. That would serve Bush’s purposes for a nominee such as Nussle. But a recess appointment might not be attractive to a judicial nominee, who would have a lifetime post if confirmed by the Senate.

Presidents have made recess appointments of more than 300 judges, but only four since the Eisenhower administration. Bush appointed two in 2004: Charles W. Pickering to the 5th U.S. Circuit Court of Appeals and William H. Pryor to the 11th U.S. Circuit Court of Appeals. Pickering retired at the end of 2004; the Senate later confirmed Pryor.

The 11th Circuit appeals court upheld Pryor’s appointment on the seventh day of a 10-day recess, saying the Constitution “does not establish a minimum time that an authorized break in the Senate must last to give legal force to the President’s appointment power under the Recess Appointments Clause. And we do not set that limit today.”

That would appear to leave in doubt how often Reid would need to convene the Senate in pro forma session this month to effectively prevent recess appointments.

President Bill Clinton made 139 recess appointments during his eight years in office. Bush had made 171 recess appointments through June 4.

Many of the nominees Bush has appointed during Senate recesses have faced opposition. Two of the most controversial were last year’s appointment of John Bolton to be ambassador to the United Nations and this year’s appointment of Sam Fox as U.S. ambassador to Belgium. Fox was a St. Louis businessman who gave money to the “Swift Boat” veterans who opposed Sen. John Kerry’s 2004 presidential campaign.

Recess appointments are “one of the reasons why relationships are so poor with the White House even among Republican senators,” said Judiciary Chairman Patrick J. Leahy, D-Vt., “They don’t talk to either the Republican or Democratic leadership of committees when they do it,” Leahy said. “I think it shows the arrogant disdaining of the Congress.”

Budget Chairman Kent Conrad, D-N.D., said he would prefer that Bush let the Senate exercise its advice-and-consent role.

“Are there reasons for recess appointments? Sure there are, in terms of national security. But there’s a reason for this process. There’s a reason the Founding Fathers set all of this up,” he said.

That’s far from a universal sentiment, especially on the other side of the aisle.

“They’ve blocked a lot of nominations and the president has decided to make recess appointments,” said John E. Sununu, R-N.H., who serves on Biden’s committee. “No one should be surprised.”

Michael Sandler contributed to this story.