JEFFERSON CITY, Mo. – The office of Missouri Attorney General Chris Koster said Monday it plans to defend the state Senate in lawsuit challenging its policy that allows it to turn away cameras from official committee meetings.

The legal challenge was filed by the liberal advocacy group Progress Missouri, which has had its cameras turned away from two committees. The group claims the Senate’s rule giving committee chairmen the arbitrary authority to turn away cameras violates state’s open records law.

“The Attorney General’s Office has communicated to Senate President Pro Tem Tom Dempsey that the AGO will provide counsel to the General Assembly and vigorously defend the legislature in this matter,” Koster’s office said in a statement.

The office’s decision to defend the Senate pits Koster, a Democrat, against Progress Missouri, a group that the Missouri Democratic Party has paid, in part, to help its political efforts.

Nanci Gonder, a spokesperson for Koster’s office, would not say whether he agreed with the Senate’s position. Instead, she said, “The Missouri Senate is our client, and the Attorney General’s Office will defend its position in this matter.”