Responding to Republican Norm Coleman's appeal to the state high court, Franken said there is no evidence that problems with absentee voting affected the outcome of the race, which a three-judge recount panel ruled the former "Saturday Night Live" writer and actor won by 312 votes, the Minneapolis Star-Tribune reported Tuesday.
"The different procedures were consistent with the different resources, personnel and technology available to each county and city," Franken's campaign said.
Franken's lawyers asked the justices to uphold the panel's ruling and order Gov. Tim Pawlenty and Secretary of State Mark Ritchie to issue an election certificate promptly, the St. Paul Pioneer Press said.
"For over four months, the citizens of Minnesota have been represented by one U.S. senator, and the effects of this delay are increasingly significant," the brief said.
While Franken calls for closure, Coleman maintains he will win once the court considers issues he raised about the absentee ballots.
Coleman claimed due process was violated, saying the three-judge panel imposed different standards for counting ballots than were used during the election and recount. In his response brief, Franken said Coleman's lawyers didn't raise a due process argument adequately during the trial, the Star-Tribune said.
Coleman's attorneys are expected to file a rebuttal this week.
Oral arguments are scheduled for June 1.