The Independence Party of Minnesota on Tuesday announced it will work against passage of a constitutional amendment defining marriage as a heterosexual union.

IP Chairman Mark Jenkins said in a statement that his group would work against passage of the 2012 ballot measure.

“Our platform declares that 'We oppose having the government impose state-sponsored morality or values on people of good conscience with differing views. This is a perfect example,” Jenkins wrote.

“We're proud to partner with all organizations working to defeat this amendment over the next 15 months,” he added.

The broad coalition of groups preparing to fight against the bill include the Democratic Farmer Labor Party, the Minnesota Association of Professional Employees (MAPE), the Libertarian Party, the Human Rights Campaign (HRC), OutFront Minnesota, the Minnesota Council of Nonprofits and various labor groups.

A coalition of mostly Christian conservative groups – including the Minnesota Catholic Conference and the Minnesota Family Council – will campaign for the amendment's passage.

Republicans Against the Minnesota Marriage Amendment, which is allied to the gay GOP group Log Cabin Republicans and former Iowa State Senator Jeff Angelo's Iowa Republicans for Freedom, will also work against the amendment.

Democratic Governor Mark Dayton also opposes the marriage ban and has pledged to support the effort to defeat it.