Kevin de Leon, leader of the California state Senate, has received the endorsement of the Service Employees International Union as he poses a primary challenge against incumbent Sen. Dianne Feinstein, D-Calif.

The SEIU is a prominent labor union, particularly in California, and announced Tuesday it was backing de Leon due to his positions on a $15 minimum wage, immigration, and environmental activism.

“Kevin de Leon is a leader who speaks up for California values. His leadership on the most pressing challenges facing California stands in stark contrast with the dysfunctional political establishment in Washington, D.C.,” said David Huerta, an executive board member with the SEIU’s California group, according to the LA Times. “He’s stood up for us and our California values again and again, and now we are proud to stand shoulder to shoulder and endorse Kevin de León to be our next U.S. senator.”

Feinstein, who has been a U.S. senator for more than 25 years, maintains a hefty financial advantage in comparison to de Leon. She began 2018 with nearly $10 million whereas De Leon had $360,000.

The California Nurses Association, another prominent labor union in California, also announced it would support de Leon.