For the second time this week, the testimony of a key witness in Republican Norm Coleman's Senate election lawsuit was halted over a failure by Coleman's attorneys to disclose contacts she had with them before the trial.

Minneapolis poll worker Pamela Howell was testifying Friday about possible double-counting of some ballots in that Democratic-leaning city when it emerged that she had had e-mail contacts with Coleman's attorneys that weren't disclosed to Democrat Al Franken's team.

The three judges hearing the case were considering whether to toss out Howell's testimony.

Franken leads Coleman by 225 votes after a statewide recount completed in December. Coleman's legal challenge is in its fifth week.

Howell's testimony was struck earlier this week because she supplied written materials to Coleman's team that were not given to Franken's in violation of trial rules. She was reinstated Thursday because the three-judge panel hearing the case deemed it accidental.

Howell has testified that she knew of an error that could have caused some voters to have two ballots included in the race. The error involves the process for handling ballots that can't be read by optical scanning machines, usually because they are damaged in some way.

In such cases, the ballots are copied by election judges, and both the original copies and the duplicates are tagged.

Howell testified that some duplicate ballots weren't marked properly, making them impossible to match up with original versions during the recount and creating the possibility both were included.

Coleman's attorneys have called Howell's testimony critical to his claim of double-counting in several precincts. Coleman's lawyers estimate those mistakes resulted in about 100 votes overall for Franken.

The back-and-forth e-mails disclosed in court on Friday showed the efforts of Coleman's team to keep information about Howell private for as long as possible. She also asked them if she would be "coached" before testifying.

In asking the judges to strike her testimony Friday, Franken lawyer David Lillehaug said: "It is clear that her testimony was the linchpin for the Coleman original-duplicate ballot issue. That linchpin has been tainted, it has been corroded."

Coleman attorney Joe Friedberg told the court the e-mails were "blown a little bit out of proportion" and didn't get at the substance of her testimony about the mishandling of ballots.

Later, the campaigns argued over a Coleman motion to reconsider all 287,000 absentee ballots cast last year. His lawyers say thousands of accepted ballots would be illegal under the standards the three-judge panel set forth in a Feb. 13 ruling.

Minnesota has now gone a full eight weeks with just one senator, with Coleman's lawsuit expected to take several more weeks.