In the wake of President Bush’s decision Wednesday to make recess appointments for three controversial federal nominees, Senate Democrats have begun studying their options for either reversing the appointments or depriving Bush of the chance to make similar moves in the future.

While no decision on how to proceed has been made by Senate Majority Leader Harry Reid (D-Nev.), Democratic aides are discussing a number of possible moves, including using a rarely invoked legal requirement that the nominations of the recess appointees be resubmitted within 40 days, subjecting them to a potential Senate vote. Democrats also are mulling keeping the chamber in session “pro forma” during future recesses to avoid further appointments.

The appointments came five days into the weeklong April recess, which is the shortest break during which a president has ever made a recess appointment. Reid announced in January that he was putting an end to the long-standing practice of multiweek recesses aside from the August break, largely to limit Bush’s opportunities to install controversial picks.

But Bush bucked that tradition of only making recess picks during longer recesses this week, appointing three nominees who had virtually no chance of clearing the Senate this year.

The White House announced Wednesday that Bush had used his constitutional authority to appoint three highly controversial picks to key federal positions, including Sam Fox as the new ambassador to Belgium. Fox, a major GOP donor, was a key financial backer of the Swift Boat Veterans for Truth, a group that emerged during the 2004 election accusing Sen. John Kerry (D-Mass.) of lying about his combat experience. Bush withdrew his nomination last week once it became clear that Fox would not make it out of the Senate Foreign Relations Committee.

The White House announced that since his nomination had been withdrawn, Fox would serve pro bono in order not to run afoul of federal rules barring certain types of recess appointments from receiving federal funds.

Although it is still unclear how Reid will respond, a senior Democratic aide warned that the administration is treading on dangerous ground.

“The White House and the Republican leadership better be careful or they’re going to find themselves without any recesses from here on out,” the aide said, adding that “Fox in particular is a real poke in the eye. For God’s sakes the guy’s nomination is not even pending before the Senate.”

Bush also named former White House Social Security adviser Andrew Biggs to serve as deputy director of the Social Security Administration. While working for the Congressional Institute — a nonprofit organization staffed by some of Washington’s top GOP lobbyists that has hosted retreats for Republican lawmakers — Biggs once wrote a paper advocating the wholesale dismantling of New Deal-era social welfare programs, starting with the Social Security program.

Additionally, Bush named Susan Dudley, anti-regulatory activist and former head of the conservative Mercatus Center, as head of the Office of Management and Budget’s Office of Information and Regulatory Affairs. OIRA is one of the most powerful offices in the executive branch with authority over the nation’s system of health, labor and environmental protections.

According to Democratic Senate aides, federal law requires the White House to resubmit nominations that have been the subject of recess appointments within 40 days after the start of the next work period. Democrats could then quickly move the nominations to the chamber’s floor and defeat them. Although it is unclear whether such a scenario would necessarily require a new nominee, it would almost certainly place significant political pressure on the White House to pull the appointments.

Additionally, aides noted that the same federal rules barring payments to Fox that have been cited by the administration also appear to explicitly not cover positions with a “fixed rate of pay,” which would include all ambassadorships.

Sen. Chris Dodd (D-Conn.) called the appointments an “abuse of executive authority” and announced Wednesday that he was seeking a legal opinion from the Government Accountability Office on whether the nominations could stand.