A threatening letter has sparked a new controversy here in San Diego surrounding the gay marriage debate. Donors who gave money to the No on Prop 8 campaign say they received blackmail letters demanding money, and the Yes on 8 campaign now says the letters were sent by their employees.

The letter from Yes on 8 came by certified mail, demanding at least $10,000. Jim Abbot knows exactly why he's being targeted - his business gave $10,000 to a group called Equality California, which supports No on Prop 9.

Jim says nearly 25 percent of his staff is gay.

"We wanted to support their freedom to marry," he said.

The letter says if Jim doesn't give an equal donation to Yes on 8, the name of his company will be published. It reads in part, "It is only fair for Proposition 8 supporters to know which companies and organizations oppose traditional marriage.

"I feel like it's blackmail, and as you can imagine, real estate business has been tough lately and to have someone come at you like this… it's very distressing," he said.

Yes on 8 confirms they sent around 30 companies the letter. A spokeswoman told News 8 they are just trying to hold their ground in a passionate race. She added that No on 8 supporters picketed the Manchester Grand Hyatt after Doug Manchester donated $125,000 thousand. The publicity caused at least one very large group to cancel its event at the hotel.

She also pointed to a popular blog that asked readers to dig up dirt on Yes on 8 supporters, see if they've contributed to less than honorable causes, or have done something otherwise egregious, with the hope they can force the Yes on 8 campaign to return their contributions, or face a bunch of negative publicity.

But News 8 couldn't find anything from No on 8 supporters demanding money from Yes on 8 supporters.

As for Jim, he stands behind his donation, and will not be making a similar one to Yes on 8.

"We're not caving... we'll support our employees. We're going to support the freedom to marry, a fundamental right to do what we can to make sure it's not taken away," he said.