Rep. Ken Buck (R-Colo.) is set to retire from Congress next week, as he revealed on Tuesday, delivering a surprising announcement that further diminishes the House GOP’s already narrow majority.

Last year, Buck, known for his divergence from party lines and vocal criticism of Republicans regarding election denialism, had initially stated his intention to leave the House at the end of his current term.

However, he has now expedited that timeline.

At 65 years old, Buck concludes his over nine-year tenure in Congress, marked by numerous contentious votes over the past year, The Hill reported.

These votes, including his role in removing former Speaker Kevin McCarthy (R-Calif.) and his opposition to the impeachment of Homeland Security Secretary Alejandro Mayorkas, placed him at odds with fellow members of the House GOP conference.

With Buck’s impending departure, the House GOP’s majority will decrease by one, resulting in a breakdown of 218 Republicans and 213 Democrats.

While the margin remains the same, Republicans will now have a narrower cushion for party-line votes, facing increased difficulty in passing messaging legislation in the coming months, as they can only afford to lose two members assuming all lawmakers are present.

Written by B.C. Begley