Leaders of the campaign to outlaw same-sex marriage in California made an offer to businesses that have given money to the state’s largest gay-rights group: Give us money or we’ll publicly identify you as opponents of traditional unions

Supporters of same-sex marriage called the tactic “an attempt to extort people” and “a bit Mafioso.”

ProtectMarriage.com, the umbrella group behind a ballot initiative that would overturn this year’s California Supreme Court decision legalizing gay marriage, targeted about 35 companies in the appeal, spokeswoman Sonya Eddings Brown said.

She called the letter “a frustrated response” to the intimidation felt by Proposition 8 supporters, who have had their lawn signs stolen and property vandalized in the closing days of the increasingly heated campaign.

Certified letters from the group this week asked companies to withdraw their support of Equality California, a nonprofit organization that is helping lead the campaign against Proposition 8.

“Make a donation of a like amount to ProtectMarriage.com which will help us correct this error,” reads the letter. “Were you to elect not to donate comparably, it would be a clear indication that you are in opposition to traditional marriage. ... The names of any companies and organizations that choose not to donate in like manner to ProtectMarriage.com but have given to Equality California will be published.”

The letter was signed by four members of the group’s executive committee: campaign chairman Ron Prentice; Edward Dolejsi, executive director of the California Catholic Conference; Mark Jansson, a member of The Church of Jesus Christ of Latter-day Saints; and Andrew Pugno, a lawyer for ProtectMarriage.com.

A donation form was attached. The letter did not say where the names would be published.

Read the full story from the Associated Press.