"I think that the 'Just Say No' for (propositions) 2, 3, and 4 had got to be counting on spending $25 million and, if they want it to pass, the unions will have to spend $12 million to $15 million or more," said University of Detroit Mercy Adjunct Professor Mike Whitty.
If the referendums passed, the propositions would make Michigan the first state to have collective bargaining as a right guaranteed by the state's Constitution, The Detroit News reported Monday.
To date, the most recent report says that groups backing referendum 2 had raised $8.1 million by July 25.
Businesses that oppose the proposition had raised $624,620.
Beside the right to collective bargaining -- Proposition 2 -- votes will also decide on Proposition 3, which would raise the bar on alternative energy mandates and Proposition 4, which would allow home healthcare workers the right to form a union.
In the meantime, the lobbying has been marked by some wild claims, a panel of journalists said.
The Michigan Truth Squad made up of journalists, said opponents of collective bargaining have made an accusation that "veers into hyperbolic," with a charge that collective bargaining would allow sexual predators to teach in Michigan's public schools.
"The biggest question is whether or not the present ability to keep pedophiles out of the classroom will be affected ... and I believe it would," said Richard McLellan, a member of the board of directors of the Mackinac Center for Public Policy, described as a conservative think tank.
"It's the Pandora syndrome -- (opponents of the propositions say) if you open the box all these demons will fly out to release a terrible scourge on the state of Michigan," said Larry Roehrig, the secretary treasurer of the American Federation of State, County and Municipal Employees, Michigan.
Notable deaths of 2014 [PHOTOS]
GM recalls 221,000 Cadillacs and Impalas