Four Indiana gay couples are suing to have their out of state marriages recognized.
The suit, filed in federal court on Friday (7 March), seeks to overturn Indiana's Defense of Marriage Act, which views same-sex marriages illegal even if recognized by other states.
Dan Canon, one of the lawyers for the plaintiffs, told the Associated Press the suit was filed due to worries about the legislature looking to add a gay marriage ban to the constitution.
Although same-sex marriage is illegal in the state last month, lawmakers considered a bill seeking to amend the constitution defining marriage as being between one man and one woman.
The legislation stalled because politicians could not decide if to include a civil union exclusion.
'I think it's fairly clear the people of Indiana cannot depend upon the legislature and the governor to do what is right, so we're turning to the federal courts to do it,' Canon said, as reported by the Associated Press.
Canon is also part of similar legal effort in Kentucky.
Jo Ann Dale and Carol Uebelhoer, two of the plaintiffs, have been together for 35 years. Six years ago the pair were married in Massachusetts, one of the 17 US states where same-sex marriages are legal.
Dale said, at the press conference announcing the suit, the lack of legal acknowledgment for their relationship makes everything, from tax returns to end of life decisions, more complicated than they need to be.
'It feels so schizophrenic not to be recognized for who you are,' Dale said.