Updated at 12:16 p.m. on March 9

Joseph Petty, the six-term Democratic mayor of Worcester, is running for a state Senate seat.

Petty released a video Wednesday morning, saying he’ll campaign to represent the 1st Worcester District. He has already filed paperwork with the state Office of Campaign and Political Finance, changing his campaign committee’s designation from mayor to state Senate.

“I have dedicated my career to public service and one thing has never changed: There is always more. More to do, more to learn, more to give,” Petty said in a statement. “I want to bring resources back to this district and common sense solutions to the challenges we face together in Central Massachusetts.”

The 1st Worcester District includes Berlin, Bolton, Boylston, Northborough, West Boylston and Worcester. So far, Petty’s only competitor is Robyn Kennedy, an executive at the social justice nonprofit YWCA Central Massachusetts. State Rep. David LeBoeuf initially expressed interest in joining the race, but has since confirmed he will instead seek reelection.

Petty’s announcement confirms months of speculation that he would launch a bid for the 1st District seat, which state Sen. Harriette Chandler has held since 2001. In January, Chandler announced she would not seek reelection, saying it’s time for someone else to represent the district.

In an interview, Petty told GBH News that Chandler will leave behind a big void after breaking barriers as the first woman to represent the district, expanding healthcare access and worker and reproductive rights. Although he said nobody can “fill her shoes,” Petty said he will focus on addressing racial and socioeconomic inequities, if elected.

“I’m not a person of color. I’m not a woman,” Petty said. “But…whether it be women issues and public health issues and also in communities of color, what I’ve been good at is bringing opportunity and fairness.”

Petty also noted he has helped bring common sense same sex education to Worcester schools, secured over a half billion dollars in new school investments and helped oversee the development of a new senior wellness center.

Still, he added the pandemic has highlighted limits to his responsibilities as mayor since Worcester’s city manager has most political and decision-making power. As state senator, Petty said he’ll have more flexibility to help his constituents in different ways.

“You can set policy. You work with the governor’s office. You work with the state delegation,” he said. “I’ll be working on policies to improve everyone’s public health, improve affordable housing.”

Although Petty has years of experience helping lead Worcester, Kennedy — his opponent — has also been involved in political decision-making. She spent two years as a legislative aid for then-Sen. Edward Augustus before working in the office of former Gov. Deval Patrick and serving six years as a policy advisor and chief of staff for former Lieutenant Gov. Tim Murray. Kennedy also was a deputy assistant secretary in the Massachusetts Executive Office of Health and Human Services.

However, Petty currently has a significant financial advantage in the race. According to the Massachusetts Office of Campaign and Political Finance, the mayor has $48,479 in campaign funds, while Kennedy has $4,505.

If he wins the race, Petty would begin a two-year term in January 2023 but would still have a year left in his term as mayor. According to state election laws, he could serve as Worcester mayor and state senator simultaneously. But he said his intent right now would be to step down as mayor.

“I guess I’ll cross that bridge when it comes to it,” he said.

If Petty does step down as mayor, At-large City Councilor and current Vice Chair Donna Colorio would take on the position. Former Counselor Matt Wally would fill Petty’s at-large council seat after finishing as the runner-up in last November’s council at-large race.