One day after filing paperwork for re-election, Illinois Democratic Rep. Luis Gutierrez - a longtime immigration advocate - announced he will retire from Congress.

“Today I’m announcing I won’t be seeking re-election,” Gutierrez said Tuesday afternoon, but added he wasn’t “retiring” from his efforts to reform immigration.

He also shot down speculation that he would run for governor of Puerto Rico, where his family is from, and said he would not make a mayoral bid for Chicago.

Gutierrez made a name for himself advocating for comprehensive immigration reform and has openly criticized the Trump administration, most recently over its handling of storm-ravaged Puerto Rico.

The 63-year-old congressman has served his Chicago district since 1993 and is a senior member of the Congressional Hispanic Caucus.

Gutierrez also was among the harshest critics of former President Barack Obama, whom he called the “deporter in chief” for ordering immigration agencies to deport hundreds of thousands of undocumented immigrants.

He disagreed with Obama’s then-chief of staff Rahm Emanuel’s decision to push for healthcare reform instead of focusing on immigration-related issues.

Gutierrez endorsed Cook County Commissioner Jesus “Chuy” Garcia to take his seat in the solidly Democratic district. Alderman Carlos Ramirez-Rosa, a former Gutierrez staffer, is also planning to run for the seat.

Gutierrez’s decision to retire gives potential replacements less than a week to collect the 1,000 signatures needed to get on the ballot in Illinois.

Gutierrez has privately hinted to colleagues for the past several years that he wanted to retire.

Earlier this year, he signaled that he felt comfortable doing so now that the Congressional Hispanic Caucus has more than 30 members, including several younger, more ambitious colleagues in safe districts who are likely to be in Congress for several years to come.

Also leaving next year is Florida Rep. Ileana Ros-Lehtinen, the most senior Hispanic female Republican in Congress.

The Associated Press contributed to this report.