Over 200 workers at Mercury Marine in Fond du Lac have signed petitions calling for a second vote on contract concessions that could keep jobs from moving away. But the International Association of Machinists and Aerospace Workers says there won’t be another vote unless Mercury makes big changes to its contract proposal. The firm says it won’t do that, and the union has until tomorrow to have another vote. Last Sunday, about 70-percent of voting members said to no to pay cuts for new workers and those returning from layoffs. Without those cuts, the company says it would move up three-fourths of the 850 outboard motor production jobs to a non-union plant in Oklahoma. The firm is also talking about moving its headquarters from Fond du Lac. Meanwhile, the Fond du Lac Reporter says it’s not true there have been fights and threats among workers inside the Mercury plant. Police and Fond du Lac County sheriff’s deputies say they’ve had no reports of such incidents.