Republican Norm Coleman's election contest begins its second week in court Monday in St. Paul.
Testimony is set to resume from Ramsey County Elections Manager Joe Mansky.
Mansky returns to undergo cross-examination by Democrat Al Franken's attorneys.
Coleman attorneys say they'll sprinkle in testimony from individual voters but wouldn't elaborate on any other witnesses.
Earlier in the trial, Mansky testified that there probably were mistakes in rejecting ballots but also said election judges were under enormous time constraints to process 31,000 absentee ballots in Ramsey County.
The Coleman camp is arguing that the court should expand the number of ballots under consideration from 654 to 11,000.
It's also challenging Franken's lead in the recount based on alleged wrongly rejected absentee ballots; double-counted ballots; and the counting of 133 missing ballots from Minneapolis.
Until a new Senator is seated, Minnesota has only one vote in the U.S. Senate. Fifth district Congressman Keith Ellison says he and his colleagues miss having a second senator and that even a single vote matters at the Capitol.
"Al Franken's a critical vote, you know. And the fact is that there are things coming up like the stimulus package and critical votes that I think we're going to need his help on. So, by being short one Senator, there's no doubt we are at a disadvantage, which is why I'm hoping that this is resolved fast," Ellison said.
Republicans have a 41 seat minority in the Senate, barely enough to block key Democratic legislation on procedural votes.