U.S. Rep. Barbara Lee filed federal paperwork Wednesday to enter the race for the California seat held by long-serving Sen. Dianne Feinstein, potentially adding another Democrat and a nationally recognized Black woman to a growing field that already includes two other House members.

Though Lee has not made a formal announcement, her entry into the contest is widely expected. She filed paperwork creating a Senate fundraising committee one day after Feinstein — at 89 the oldest member of Congress — announced she would step down after her term ends next year.

Lee “is filing preparatory paperwork and her announcement will come before the end of the month,” spokeswoman Katie Merrill said.

Lee would join Democratic U.S. Reps. Katie Porter and Adam Schiff in the contest, who earlier announced their candidacies for the seat that Feinstein has held for three decades.

Lee, 76, is perhaps best known for being the only member of Congress to vote against the authorization for the use of military force after the terrorist attacks of Sept. 11, 2001.

She is the highest-ranking Black woman appointed to the House Democratic leadership, serving as co-chair of the Policy and Steering Committee.

She has long been on outspoken defender of abortion rights. In 2021, she was one of several members of Congress who shared personal testimony about their own abortions during a congressional hearing.

Lee became pregnant at age 16 in the mid-1960s. Abortion in California was illegal at the time, so a family friend helped send her to a “back-alley clinic in Mexico,” she said at the time.

She had no ill effects from the procedure, but she said many other women weren’t so lucky in that era.

“In the 1960s, unsafe septic abortions were the primary killer — primary killer — of African American women,” Lee said.