Senate Democrats declared victory Monday and discussed plans to seat comedian-turned-politician Al Franken (D) on Tuesday despite GOP warnings of an imminent legal challenge to his slim recount victory against Sen. Norm Coleman (R-Minn.).

The state canvassing board declared Franken the winner over Coleman by 225 votes on Monday afternoon, but Republicans say the announcement is just the beginning of a long, litigious road. Franken and Coleman have been trading leads in the two-month-long statewide recount. The contest will determine whether Senate Democrats will have a pivotal 59th seat in the 111th Congress.

In a conference call with reporters Monday evening, Coleman recount attorney Tony Trimble said the campaign planned to file an election contest within 24 hours. Under Minnesota law, campaigns have one week after the canvassing board’s report to contest the election to a three-judge committee. Minnesota Gov. Tim Pawlenty (R) must also sign off on the certification — a move that he will not make unless the contests are resolved.

“The actions today by the canvassing board are but the first step in what, unfortunately, will now have to be a longer process,” Trimble said. “This process isn’t at the end; it is now just at the beginning. We will contest the results of the canvassing board; otherwise, literally millions of Minnesotans will be disenfranchised.”

Trimble said the Coleman campaign would contest the results based on what it believes were inconsistencies in the recount: A “double voting” issue that allegedly netted Franken about 100 votes, missing ballots in a Minneapolis precinct from election night that allegedly netted Franken about 35 votes, and inconsistencies in the inclusion of hundreds of wrongfully rejected absentee ballots in the recount.

“If the canvassing board had resolved all these issues, then the process might be completed,” Trimble said. “But the board has deferred the resolution of those issues for the contest phase provided for in Minnesota law. Since the process is far from complete, there can be no confidence in the current results of the United States Senate recount, and we will file a contest within the next 24 hours to promptly correct those problems and inaccuracies.”

Coleman’s campaign had yet another setback Monday prior to the canvassing board meeting, when the state Supreme Court ordered that about 650 previously uncounted absentee ballots could not be included in the recount.

The court ruled that because the campaigns could not agree on which absentee ballots would be added to the recount before the deadline, none of the additional ballots requested by Coleman could be included. But the court also stated that the matter could be brought up in an election contest.

Coleman, who was on Capitol Hill meeting with Republican leaders Monday, is scheduled to make a public statement today in Minnesota — one of his first appearances since the recount began.

In a short statement delivered from his St. Paul, Minn., home on Monday afternoon, Franken said he was “proud and humbled” to serve Minnesota in the Senate. He said that despite forthcoming legal proceedings, he would begin as soon as possible.

“After 62 days, after the careful and painstaking hand inspection of nearly 3 million ballots, after hours and hours of hard work by elections officials and volunteers across the state, I am proud and humbled to stand before you as the next Senator from Minnesota,” Franken said.

According to a Democratic source with knowledge of Franken’s whereabouts, the Democrat had not yet booked a flight to Washington, D.C., and had not made plans to come to the Capitol today when Members of the 111th Congress will be sworn in.

Nonetheless, Senate Majority Leader Harry Reid (D-Nev.) will attempt to seat Franken as the junior Senator from Minnesota — a move that will almost certainly be blocked by Republicans and could set a sour note to the start of the new Congress, Democratic leadership aides said Monday.

Although a Reid spokesman said Monday afternoon that no final decision had been made, Reid himself seemed to indicate that Democrats would look to seat Franken today.

“Al Franken is ahead by 250 votes,” Reid said, noting that he has been involved in close elections himself. “There comes a time when you have to acknowledge that the race is over. The race in Minnesota is over.”

But with Pawlenty refusing to sign a certification of the vote until Coleman’s pending legal challenges are resolved, Reid finds himself in the awkward position of seating Franken while refusing to seat embattled Illinois Gov. Rod Blagojevich’s (D) pick of former Illinois Attorney General Roland Burris (D) to replace President-elect Barack Obama, in part because Burris’ appointment has not been certified by state officials.

“Until [Burris] gets a certificate, he is not a Senator,” Reid spokesman Jim Manley said earlier this month.

Senate Minority Leader Mitch McConnell (R-Ky.) echoed that position Monday.

“The race in Minnesota is not over. An election certification is not issued until litigation is resolved,” McConnell said. “It needs to be decided in Minnesota and not the United States Senate.”

While McConnell declined to get into specifics of how he and his colleagues will respond to Reid’s effort to seat Franken, Democratic and Republican aides alike predicted that one or more members of the GOP Conference would formally object today to his seating.

At that point, Reid and his colleagues would be faced with the choice of letting the objection stand and leaving the seat vacant or attempting to pass a resolution referring the matter to the Rules Committee — which is chaired by former Democratic Senatorial Campaign Committee Chairman Charles Schumer (N.Y.).

Referring the issue to Rules would make Franken’s seating subject to debate — meaning that, even if he is ultimately certified by Pawlenty as the winner, Republicans could filibuster his seating when it finally occurs. As a result, Democrats could opt to simply allow the objection to stand in the hopes that a legal resolution occurs well before any Rules Committee action and subsequent floor fight would take place.

Emerging from a late Monday meeting with Coleman and McConnell, National Republican Senatorial Committee Chairman John Cornyn (Texas) said Coleman remains committed to challenging the vote tally.

“He’s determined to make sure that every vote is counted. The decision won’t be made until” the three-judge panel makes a decision on his pending appeal, Cornyn said.

Coleman declined to comment on the meeting.

Veteran GOP aides warned that any effort to seat Franken today could be an early blow to the good will that Obama has been attempting to build between the two parties.

“This is the United States Senate, not Harry’s debating society,” one aide said. “You can’t simply invite someone to attend because you like them — and that’s pretty much what Democratic leaders are trying to do with Franken.”

Jessica Brady contributed to this report.