Four gay and lesbian couples on Wednesday filed a federal lawsuit challenging Montana's ban on gay marriage.

Plaintiff couples in the case are Angie and Tonya Rolando of Great Falls, Shauna and Nicole Goubeaux of Bilings, Ben Milano and Chase Weinhandl of Bozeman and Sue Hawthorne and Adel Johnson of Helena. The Goubeauxs are raising 1-year-old Aden, while Tonya and Angie, who share a last name but are not married, have two children from previous marriages.

The American Civil Liberties Union (ACLU) of Montana is representing the couples in the suit, Rolando v. Fox. Plaintiffs in the suit say the state's 2004 voter-approved constitutional amendment limiting marriage to heterosexual couples violates their constitutional rights.

Montana Governor Steve Bullock, a Democrat and not a named defendant, said he welcomed the lawsuit.

“The time has come for our state to recognize and celebrate – not discriminate against – two people who love one another, are committed to each other, and want to spend their lives together,” Bullock said in a statement.

Democratic Senators John Walsh and Jon Tester also said in statements that they support the lawsuit.

Attorney General Tim Fox, a Republican and a defendant in the complaint, has not said whether he'll defend the ban in court. However, Fox has previously called on officials to defend such bans.

According to the Human Rights Campaign (HRC), only one state, North Dakota, remains without an active lawsuit challenging its marriage equality ban. A challenge in South Dakota, which also doesn't have an active case, is being planned.