Rep. Ken Buck (R-Colo.) said Tuesday he will resign from Congress later this month rather than serve out the remainder of his term through 2024.

Why it matters: The surprise announcement will cause House Republicans' already razor thin majority to dwindle even further.

What he's saying: "Today, I am announcing that I will depart Congress at the end of next week," Buck said in a statement posted to social media.

• "I look forward to staying involved in our political process, as well as spending more time in Colorado with my family."

Zoom in: Buck told Axios in an interview that he sees "an opportunity to get involved in this cycle and help change the way we elect candidates."

• He denied rumors that he is joining No Labels, the centrist group planning a third-party presidential ticket, but said Americans "are upset about Trump as a candidate and Biden as a candidate."
• "We have really big problems that need to be solved and we've got to get the type of person who wants to solve problems as opposed to throw bombs," Buck said.

By the numbers: Buck's resignation will bring Republicans down to 218 seats to Democrats' 213, meaning Republicans can afford just two defections on any given party-line vote.

• Democrats are likely to get to 214 seats in an April special election to replace Rep. Brian Higgins (D-N.Y.), who resigned in February.
• Republicans are then set to pick up seats in May and June elections to replace House Speaker Kevin McCarthy (R-Calif.) and former Rep. Bill Johnson (R-Ohio), respectively.

Between the lines: Buck, a member of the right-wing Freedom Caucus, has emerged as a lonely GOP critic of House Republicans' efforts to impeach President Biden and Homeland Security Secretary Alejandro Mayorkas.

• He said last November he planned to retire from Congress this year rather than run for another term.

Go deeper: Lawmakers are ditching Congress at a record pace

Editor's note: This story has been updated with the latest.