Donors have poured more than $18 million into campaigns for and against constitutional amendments voters will face next week, making those ballot fights the most expensive Minnesota has ever seen.

More than half of the cash has gone to the fight against an amendment that would ban same-sex marriage. Following closely are groups fighting for control of the Legislature -- they have spent more than $14 million to sway Minnesotans.

That money has resulted in Minnesotans being unable to watch television, pick up the phone or check the mail without someone telling them how to vote. In the final week before voters make their wishes known, the tension -- and spending -- will only grow as high-profile donors and activists weigh in.

Released Tuesday, the state finance reports tell a lopsided story of fundraising and spending. With only a few exceptions, liberal and Democratic interests outpaced conservative and Republican ones in raising and spending money on Minnesota campaigns.

Minnesotans United for All Families, the group trying to defeat the measure, has raised more than $10 million -- with $2.75 million of that coming in the past month, according to reports filed Tuesday. The group also said it had received $1.2 million of in-kind contributions and reports having more than $300,000 on hand.

"As we enter the final days of this campaign, we will continue to remind Minnesotans what is really at stake -- and that's whether we're going to vote, in 2012, to limit the freedom to marry for one group of people," said Richard Carlbom, Minnesotans United campaign manager.

Minnesota for Marriage, the lead group pushing the measure, had technical problems transmitting their report to the campaign finance agency, spokesman Chuck Darrell said. Darrell said the group has raised $5 million since the campaign began.

Campaign chairman John Helmberger said the group lately has experienced a "surge in the number of contributors and contributions [that] has allowed us to step up our TV, billboard and radio ads that focus on what happens ... when same-sex marriage has been imposed elsewhere."

Among more than 62,000 donors who have given to fight the marriage amendment are some big names. New York Mayor Michael Bloomberg gave $125,000, Bill and Robert Pohlad gave a combined $260,000 and Alida Messinger, a big DFL donor and Gov. Mark Dayton's ex-wife, gave $200,000. National groups, including the Human Rights Campaign and the Freedom to Marry PAC, have given $1 million-plus.

The big dollars have paid for dozens of staffers, more than $4.7 million in TV ads and $100,000 on online advertisements. The push is so huge that the group has spent about $90,000 on T-shirts alone.

The pro-amendment side's most powerful ally continues to be the Catholic Church, which has given the campaign about a fifth of its total budget so far. The church has long gathered smaller donations from Catholic dioceses and Knights of Columbus halls statewide to contribute to the fight to define marriage not just in law but in the Constitution. The Minnesota Family Council has also donated at least $750,000.

Several members of the news media also contributed to the anti-amendment group in recent months.

Claude Peck, a Star Tribune arts editor, gave $165 to Minnesotans United for All Families. Pioneer Press movie critic Chris Hewitt gave the group $130. At least eight staffers at Minnesota Public Radio, and its parent company, American Public Media, combined to give the group more than $1,500. Among those donors were John Pearson, a director of digital services at Minnesota Public Radio and American Public Media. He gave $250 in September.

Voter ID lower-key

Efforts for and against the photo ID amendment, which would require voters to present identification at the polls and would make other changes to Minnesota's voting system, have been less costly but are seeing their own surge.

ProtectMyVote, the primary campaign in favor of the amendment, has raised about $1.5 million. The vast majority of that has come from a single donor -- Joan Cummins, wife of longtime Republican businessman Bob Cummins, who gave the group $1.3 million.

Our Future Our Vote, the main campaign against the amendment, raised about $2.6 million. Unions and national Democratic groups, including and America Votes, have contributed heavily to the group. Messinger, who gave $200,000 to the campaign against the marriage amendment, gave $175,000 to fight voter ID.

Heading into the final week, Democratic organizations have raised and spent far more than Republican ones for state activity. The DFL Party and the DFL committees focused on the Legislature have spent $12.7 million. The Republican party and the two legislative committees have spent about half that.

As of last week, Republicans also had far less to spend. The three Democratic campaign committees had about $2.7 million left for the campaign's final weeks. The three Republican groups had less than $1 million.

The Republican figures are hampered by a state party that had about $3,000 cash on hand and nearly $2 million in debt or unpaid bills.

According to finance reports, Republican-friendly organizations have been making up some of the gap the party left behind.

Two GOP-friendly groups, the Freedom Club and the Minnesota's Future, have raised almost $3 million for legislative races. Minnesota's Future is backed by big business groups and GOP-leaning business leaders. Joan Cummins also gave Freedom Club more than $1 million.

The backers of the biggest independent groups pushing for Democrats to control the Legislature also hold much in common with the big donors to the amendments. Union groups and Messinger make up much of the funding for Alliance for a Better Minnesota's $3 million in contributions.

Rachel E. Stassen-Berger Twitter: @rachelsb