ST. PAUL, Minn.— A Republican state lawmaker is introducing a bill to establish civil unions for Minnesota gay couples as an alternative to legalizing same-sex marriage.

Republican Rep. Tim Kelly of Red Wing planned to unveil his proposal at a Wednesday press conference at the Capitol. He said his bill has support from lawmakers in both parties.

Kelly was one of four Republicans who voted against the constitutional amendment to ban gay marriage when the Legislature put it on the ballot in 2011. But he has said that gay marriage supporters overreached when they turned from defeating the constitutional ban to pushing for legal gay marriage, arguing that opposition to putting the ban in the constitution didn’t necessarily equate to supporting gay marriage.

But Sen. Scott Dibble, chief author of the gay marriage bill, said civil unions are insufficient. “Civil unions are a separate and unequal status,” he said. The Minneapolis Democrat said civil unions would be a “legal construct” specific to Minnesota that couldn’t be recognized outside Minnesota or give them access to federal rights and benefits related to marriage, particularly if the U.S. Supreme Court strikes down the federal Defense of Marriage Act as its currently considering.

“We’re moving forward with marriage this year,” Dibble said. “The time is right.”

The Colorado Legislature voted to legalize civil unions last month and they will be available to gay couples there starting May 1. Like in Minnesota, Democrats hold the governor’s office and control the Legislature. But the state also has a ban on gay marriage in its constitution, which would have made a push for full gay marriage rights there much more difficult.

According to the Human Rights Campaign, a total of eight states allow civil unions or domestic partnerships that mimic full marriage rights. Nine states and Washington, D.C., directly allow gay marriage.