Updated

Norm Coleman filed a lawsuit Tuesday in a Minnesota court  to challenge the results of the state's Senate recount -- a move expected to block Al Franken's path to the U.S. Senate, at least temporarily.

The state Canvassing Board on Monday gave Franken the victory over Coleman, the incumbent senator, by a 225-vote margin, however, Franken was not seated Tuesday in the U.S. Senate because the certification of the race requires seven days for validation.

Coleman told reporters that the Canvassing Board wrongly double-counted some ballots for Franken and accepted 650 absentee ballots that were improperly registered.

"As of today, not every valid vote has been counted and some have been counted twice," Coleman said during an afternoon news conference after filing the suit in Ramsey County Court. "Under Minnesota law, there can be no valid election certificate if an election contest is filed."

Senate Majority Leader Harry Reid called Tuesday for the Coleman to concede, but he responded that "this race will be determined by Minnesota voters -- not by Harry Reid."

The Coleman campaign said it is confident that the Republican will emerge the winner once the lawsuit is settles in state court. The lawsuit alleges that the Canvassing Board made mistakes when determining voter intent on challenged ballots, that ineligible voters cast ballots and that some absentee ballots were erroneously opened early, raising chain-of-custody concerns.

"Something greater than expediency is at stake here," Coleman said. He added: "Democracy is not a machine. Sometimes it's messy and inconvenient, and reaching the best conclusion is never quick because speed is not the first objective. Fairness is."

The Franken campaign responded to Coleman's announcement of a lawsuit by saying, "Desperate times call for desperate measures."

"They make a series of unsubstantiated and, frankly, unclear allegations," Franken attorney Marc Elias said, adding that he thinks the lawsuit will not change the current ballot tally.

Earlier Tuesday, Minnesota Secretary of State Mark Ritchie, a Democrat, told FOX News that he has no doubt that the five-person Canvassing Board, which he led, properly counted the ballots and that Minnesotans chose Franken. But he agreed that the matter can only be resolved in the courtroom.

On Monday, Senate Democratic Leader Harry Reid's spokesman said Reid hoped Coleman would accept defeat.

Senate Republican Leader Mitch McConnell, on the other hand, said he doesn't expect an election certificate to be issued until the litigation is over.

"The only people who have pronounced the Minnesota Senate race over are Washington Democrats, and the candidate who is the current custodian of the most votes," McConnell said in a written statement released Tuesday. "The people of Minnesota certainly don’t believe this is over."

The Associated Press contributed to this report.