Former Sen. Norm Coleman's (R) campaign filed its appeal with the Minnesota Supreme Court Thursday, arguing that state canvassers failed to count votes in a uniform manner in the contested Senate race.

Coleman argued that state courts used different standards in accepting absentee ballots and that the court's own rulings on the legality of votes where in error.

A three-judge panel overhearing Coleman's challenge to Democrat Al Franken concluded that Franken had a 312-vote lead in the contested race.

The state Supreme Court has scheduled oral arguments for early June. Visit the Minnesota state courts' website for more information on the filing.