"There are solutions to improve military and overseas voting without expanding dangerously insecure voting technology," the group wrote in a letter to members of the Senate Armed Services Committee this week.

"We believe that servicemembers deserve the highest standard of safe and verifiable voting. For the foreseeable future, internet voting cannot meet that standard, and places military voters' votes — and the trustworthiness of elections themselves — at risk."

The effort, which includes groups like Protect Democracy and the U.S. Vote Foundation as well as 27 former state election officials and academics, comes as the Senate is preparing to complete its draft of the massic defense policy bill in the next few weeks.

House lawmakers passed their draft last month, and included provisions to provide "end-to-end electronic voting services for absent uniformed services voters" in locations with limited postal options.