ST. PAUL — A national group of prominent GOP donors that supports gay marriage is pouring new money into lobbying efforts to get Republican lawmakers to vote to make it legal.

American Unity PAC was formed last year to lend financial support to Republicans who bucked the party’s longstanding opposition to gay marriage. Its founders are launching a new lobbying organization, American Unity Fund, and already have spent more than $250,000 in Minnesota, where the Legislature could vote on the issue as early as next week.

The group has spent $500,000 on lobbying since last month, including efforts in Rhode Island, Delaware, Indiana, West Virginia and Utah.

Billionaire hedge fund manager and Republican donor Paul Singer launched American Unity PAC. The lobbying effort is the next phase as the push for gay marriage spreads to more states, spokesman Jeff Cook-McCormac told The Associated Press.

“What you have is this network of influential Republicans who really want to see the party embrace the freedom to marry, and believe it’s not only the right thing for the country but also good politics,” Cook-McCormac said.