Three years after losing re-election as mayor of Jacksonville, Alvin Brown is going to run for Congress against first-term U.S. Rep. Al Lawson.

Both candidates are Democrats and would run in the 5th Congressional District, which stretches from Downtown Jacksonville to Tallahassee across the top of Florida -- the district carved out by the Florida Legislature during redistricting in 2016.

The district survived several legal challenges by former U.S. Rep. Corrine Brown, who was ultimately defeated by Lawson, a former state representative and senator in the Tallahassee area.

Rontel Batie, a former Corrine Brown staff member who testified as a defense witness at her trial, announced last month he would run for the seat.

Alvin Brown's announcement included a statement why he will make another run for public office.

“These challenging times call for each of us to stand up and speak out about the kind of community in which we want to live. When I look at our region, our state, and our country, I know that we can do better,” Brown said. "As mayor, I prided myself on the fact that City Hall was the ‘people’s office’ and believe the same should apply in the U.S. Capitol. I am committed to giving the people a real voice and representation in Washington.”

Florida's Division of Elections shows no candidates had filed paperwork to run in the district, but News4Jax found a website and Twitter account for the Brown for Congress campaign.

Reached by News4Jax late Tuesday, Lawson said had heard rumblings for months that Alvin Brown would enter the race, so he is not surprised. He had also heard that Batie and Boys and Girls Club executive from the Madison or Gadsden, Florida, areas was planning to run.

"I've never feared opposition. I think opposition is always good for any candidate. I have a record to run on," Lawson said after his first year in Congress. "I’ve been able to work with the Democrats and Republicans on a bipartisan basis to get a of lot of things done, and especially, in working with (U.S. Rep. John) Rutherford."

News4Jax political analyst Rick Mulaney said Brown will be a formidable opponent.

"Alvin Brown brings a lot to the table," News4Jax political analyst Rick Mulaney said. "He's a proven fundraiser.... He's a bit of a centrist, and he's got some great name recognition in Duval County."

Florida’s 5th Congressional District includes Baker, Gadsden, Hamilton and Madison Counties as well as parts of Columbia, Duval, Jefferson and Leon Counties. The Brown campaign said it will hold a formal kickoff event in the coming weeks.

Alvin Brown, an Edward Waters College and Jacksonville University graduate, was elected in 2011 as Jacksonville's first black mayor. He previously had worked in Washington as an intern for Bill Nelson while Nelson was a member of the United States House. He worked on the staff of the Clinton-Gore transition team in 1992 and 1993, and then worked in various positions in Clinton administration, including the U.S. Department of Commerce, Housing and Urban Development and the Agriculture Department.