If it doesn't pass, members can strike as early as Monday morning. SEIU-73 represents more than 700 building and food service workers.
Union reps say the contract is the university's final offer. Right now, they feel members could vote in either direction.
"You can look at it either way. A strike is a tough thing. This contract in these economic times would also be tough, but that's why we let the members decide," said union representative Ricky Baldwin.
The union has been negotiating with UI since June. The final round of voting happens Sunday. The results should be available later the evening.