Opponents of a proposal to write collective bargaining rights for workers into the Michigan Constitution have filed a challenge to keep it off the November ballot.
Citizens Protecting Michigan's Constitution sent a letter Thursday to Secretary of State Ruth Johnson asking her to reject the 684,286 signatures filed last week to get the "Protect Our Jobs" petition on the ballot.
Opponents say the union-backed petition language doesn't make it clear that up to 80 Michigan laws could be changed if voters approve the measure.
Dan Lijana of Protect Our Jobs says the challenge comes from "corporate interests" trying to make an "end run" around the democratic process. He says twice the minimum number of signatures were submitted.
The secretary of state's office is reviewing the letter.