WICHITA, Kan. (AP) — Another influential agricultural group is backing the Republican primary challenger to U.S. Rep. Tim Huelskamp in the sprawling 1st District of western and central Kansas.

The Kansas Farm Bureau’s political arm, Voters Organized to Elect Farm Bureau Friends, announced Friday its endorsement of Great Bend obstetrician Roger Marshall.

The Kansas Livestock Association has also endorsed Marshall. The two groups did not endorse a candidate when Huelskamp ran for re-election in 2014.

Huelskamp’s campaign did not immediately return phone and email messages.

Huelskamp, a tea party favorite, has been losing support in his mostly rural district since he was removed from the House agricultural committee by his Republican colleagues.

Kansas Farm Bureau president Rich Felts says endorsements are based on county affiliates’ recommendations from across the state.