Rep. Ken Buck, a Republican who represents Colorado’s 4th Congressional District, says he will resign before his term is up. Buck had previously announced he would not seek reelection at the end of his term, which ends in November.

Now Buck says his resignation will be effective on March 22.

Buck’s decision to step aside further narrows Republicans’ already slim majority in the lower chamber, from three seats to two.  

Buck initially released a short statement about his decision but it didn’t give an explanation why he came to it.

“It has been an honor to serve the people of Colorado’s 4th District in Congress for the past 9 years. I want to thank them for their support and encouragement throughout the years. Today, I am announcing that I will depart Congress at the end of next week. I look forward to staying involved in our political process, as well as spending more time in Colorado and with my family,” he said.

Buck made an appearance on CNN and said his recent experience in Congress has been filled with problems.  

Rep. Lauren Boebert, a Republican who represents Colorado’s 3rd Congressional District, is leaving her district to run for Buck’s seat. The Republican primary election takes place in late July.

Colorado’s 4th Congressional District includes most of the rural eastern half of Colorado and the heavily populated Douglas County in the southern part of the Denver metro area. It also includes the city of Loveland in Nothern Colorado. Aside from Democrat Betsy Markey, who served from 2009 to 2011, the district hasn’t seen a Democratic representative since 1973.