New York City Mayor Bill de Blasio on Friday endorsed Diana Ayala for an open city Council seat that includes parts of the South Bronx and East Harlem.

The district is being vacated by outgoing Council Speaker Melissa Mark-Viverito, who is seeking a district leader post.

“I am truly humbled to have the support of Mayor Bill de Blasio. Now more than ever, strong progressive leaders must take a stand to defend the rights of all New Yorkers,” Ayala said.

“From starting universal Pre-K to making our city safer to building housing that is truly affordable for working families, we have been building a fairer and more just City with the Mayor’s progressive leadership. I am excited to continue delivering for my neighbors as the next Councilwoman for East Harlem and the South Bronx.”

In giving his endorsement, de Blasio pointed to Ayala’s resume on housing issues.

“Diana Ayala is the best candidate to carry on the legacy of Melissa Mark-Viverito and be a forceful advocate for NYCHA residents and increased affordable housing. Her personal story of overcoming adversity to provide for her family and community, and her proud roots in NYCHA and city public schools, have formed a true backbone to take on powerful interests and deliver for El Barrio and the South Bronx,” de Blasio said in a statement.

“We need progressive leaders like Diana who will be tireless champions for working families and vocal antagonists to Trump extremism which threatens our very core. I am proud to endorse her, and look forward to working with her on the City Council.”