An official is expected to make her final determination on whether longtime Congressman John Conyers should be on the Aug. 5 primary ballot.
Wayne County Clerk Cathy Garrett is to decide Tuesday.
She issued a report last week finding Conyers is more than 400 signatures short of 1,000 needed. The 84-year-old Democrat is at risk because officials believe two people don't appear to have been registered voters when they circulated petitions.
The Rev. Horace Sheffield III's staff filed the challenge.
Conyers would have three days to appeal Garrett's ruling to the Michigan Secretary of State.
Federal court actions, meanwhile, are taking aim at the requirement that petition collectors be registered voters.
Conyers first was elected to the House in 1964. He represents Michigan's 13th district, including Detroit and several suburbs.