Denver City Councilwoman Shontel Lewis will run for mayor next year rather than defend her council position, according to an affidavit she filed with the city.

The race will pit Lewis against Mayor Mike Johnston, who was elected in 2023 and has said he intends to run for a second term. With her candidacy filing Thursday, she joins several other mayoral challengers, including repeat progressive candidate Lisa Calderón.

Lewis, who was endorsed by the local chapter of the Democratic Socialists of America when she ran for the council in 2023, may be hoping to ride the momentum of that group’s recent successes in the city. DSA member Melat Kiros stunned the nation when she defeated longtime U.S. Rep. Diana DeGette in the Democratic primary election to represent Colorado’s 1st Congressional District, which consists mostly of Denver voters, on June 30.

Kiros joined a wave of other DSA-backed candidates across the country who have defeated more moderate Democrats in recent months or have active challenges pending. It’s not yet clear whether the Denver DSA will endorse Lewis in her mayoral bid.

Attempts to reach Lewis for comment Friday were unsuccessful. Late Friday afternoon, she posted an announcement video on Instagram.

“I would be lying if I didn’t tell y’all, I am absolutely terrified,” she said. “And also I am absolutely in such gratitude to be in a space to be able to make this journey, in this moment, with community — to make sure we raise the standard of what’s possible in our communities and what we should be expecting from our government.”

Lewis had teased her announcement by creating a new Instagram account for her campaign earlier in the week, under the handle @shontelforthepeople, and posting a video that withheld the office she was going to run for next.

She was elected to represent Denver’s District 8, which consists of much of northeast Denver, including Central Park, Park Hill and Montbello, in 2023. Her term doesn’t end until mid-2027, but because she can’t concurrently run for reelection to that seat, her decision to run for mayor means she won’t serve another term in that role.Before joining the council, Lewis served as an elected director for the Regional Transportation District and as vice president at the Colorado Coalition for the Homeless.

Lewis has been one of the most progressive voices on the left-leaning council. She has helped shape several major council decisions, including recent municipal sentencing changes, a ban on law enforcement using facial coverings and the city ending a contract with the Salvation Army. She also has made a point of calling out every instance in which the city has reached a legal settlement over police misconduct, reading out a total of all taxpayer dollars that have been used to pay out those settlements each year.

Johnston told The Denver Post last year that he planned to run for reelection, but he hasn’t filed for the position formally. A spokesman for Johnston sent out a statement Friday in response to Lewis’ campaign.

“Mayor Johnston has taken on Denver’s toughest challenges — and delivered,” Jon Ewing said. “In just three years, his administration has reduced street homelessness to historic lows, dramatically reduced violent crime and auto theft, and stood up to Donald Trump’s attacks on Denver’s values. There is more work ahead, and Mayor Johnston will keep fighting alongside Denverites to make our city more affordable, vibrant and full of opportunity for everyone who calls it home.”

Eight other people have filed paperwork to run, including Calderón, who has run for mayor in the two previous elections.