Two married gay couples have filed a lawsuit to overturn a Kansas policy that prevents them from filing joint state income tax returns.

The lawsuit in Shawnee County District Court contends that the Department of Revenue’s policy is discriminatory and violates the couple’s rights to equal protection. The lawsuit, which was filed Monday, also questions whether the department had the authority to set the policy through a notice in October giving guidance for same-sex couples.

The department was reviewing the filing Tuesday and did not immediately comment.

The couples are Michael Nelson and Charles Dedmon of Alma and Roberta and Julia Woodrick of Lawrence. Both couples were married in California.

The Kansas Constitution says the state cannot recognize same-sex marriages, but the lawsuit notes that the federal government does.