Rep. Darrell Issa, a Republican from California and one of the state’s most recognizable GOP lawmakers, has ended his reelection bid ahead of the state’s congressional filing deadline.

The move comes shortly before the deadline for candidates to file paperwork to appear on the ballot in the upcoming election. With Issa stepping aside, the seat representing California’s 48th Congressional District is expected to become an open race.

Issa, 71, has served multiple stints in the U.S. House of Representatives and has been a prominent conservative voice during his time in Congress. He first entered the House in 2001, representing a district in northern San Diego County, and became widely known for his role leading oversight investigations during the Obama administration.

During that earlier period in Congress, Issa served as chairman of the House Oversight Committee, where he oversaw a series of high-profile inquiries into federal agencies and policies.

After losing his seat in 2018 during a challenging election cycle for Republicans in California, Issa returned to Congress two years later by winning an election in a neighboring district.

The 48th Congressional District, which covers parts of coastal Southern California, has grown increasingly competitive in recent election cycles as political demographics in the region have shifted.

Issa’s decision not to run again is likely to prompt a scramble among potential Republican and Democratic candidates seeking to succeed him. Because the decision came close to the filing deadline, prospective contenders have had limited time to organize campaigns and submit the necessary paperwork.

Issa has remained active in Congress in recent years, particularly on issues related to national security and foreign policy.