The Minnesota Senate's attempt to broaden the type of technology that could be used to identify voters at the polls is in jeopardy.

Sen. John Howe, R-Red Wing, offered an amendment on Friday that would allow voters to present government-issued photographic identification "or equivalent" to meet the requirement. Howe said his goal was to allow for changes in technology, and to allow the state to move from photo ID cards to newer and better identifying technology when it comes along.

His amendment was approved by a 63-3 vote when the Photo ID measure passed the Senate on Friday.

But when the Senate named members of a joint House-Senate conference committee to iron out differences between the two bills and draft a final version, Howe was left off the Senate team. Instead, two of the three senators who voted against his amendment, Sen. Dave Thompson, R-Lakeville, and Sen. Warren Limmer, R-Maple Grove, were named to the five-member Senate group.

"Certainly I'm disappointed that I'm not on the conference committee," Howe said on Tuesday. "I'm concerned that we're going to put a specific technology into our constitution that is not going to allow us for advancements."

"I'm expecting that we'll probably hear it back this week," he said.

Rep. Mary Kiffmeyer, R-Big Lake, the House sponsor, said she opposes Howe's measure and will argue that it not be included in the final version.

Both houses passed separate versions, proposing an amendment to the Minnesota constitution to require all voters to show a photo ID at the polls in the future. Constitutional amendments must be approved by voters to take effect, and the 2013 Legislature would spell out the details of how the requirement would work.

The conference committee will attempt to write a single version based on the two bills and submit it back to the two houses. If both houses pass the same language, the proposed amendment goes onto the November ballot.