Longtime Bronx Rep. José E. Serrano revealed Monday that he has been diagnosed with Parkinson's disease, and says he will not seek re-election in 2020.

The congressman is currently serving the 15th District, but has been in public service for the last 45 years.

Serrano pushed for equal opportunity and fair treatment as the longest-serving Puerto Rican in Congress. In 1992, Serrano passed legislation mandating voter materials continue to be provided in different languages. He worked to restore the Bronx River and was actively involved in ending the embargo against Cuba.

In a statement he said in part, "After my diagnosis, I initially planned to continue my work representing the people of the South Bronx far into the future- a responsibility that brings me great joy. Although this disease has not affected my work in Congress, over the last few months I’ve come to the realization that Parkinson’s will eventually take a toll, and that I cannot predict its rate of advancement.  Because of this uncertainty, I do not intend to seek re-election in 2020. I do intend to serve the remainder of my term in the 116th Congress.”

The statement continued, "I am grateful to all my colleagues for their dedication to our community and for the years we spent working together on so many important issues. To my constituents -- it has been the honor of my life to serve you."

Serrano says he will continue to use his time left in Congress to fight for climate change research, a fairer justice system and an accurate 2020 census count to give marginalized communities a voice in Washington.