City Councilor Edward Suslovic has taken out nomination papers to challenge incumbent Portland Mayor Michael Brennan in November.

Brennan, who took out nomination papers Wednesday, formally announced his re-election bid June 3 at the Ocean Gateway terminal on the city’s Eastern Waterfront. He said he needed another term to work on several of his initiatives, including the Portland ConnectED education program, the Growing Portland workforce development plan and the Mayor’s Initiative for a Healthy and Sustainable Food System.

Days later, Suslovic said he was “strongly considering” challenging the incumbent. Suslovic blamed Brennan for what he called low morale among city staff, a high rate of turnover among department heads, division among community members about real estate development, and unsustainable budget problems. Before taking out nomination papers Thursday, Suslovic said a formal campaign kickoff was still being planned.

Washington Avenue resident Chris Vail also has taken out nomination papers. Vail, a Portland firefighter, was one of 15 candidates in the 2011 mayoral election.

Other city races are also beginning to take shape.

Pitt Street resident Spencer Thibodeau, a 27-year-old real estate attorney at the Portland-based law firm Verrill Dana, has taken out papers for the District 2 City Council seat, representing the West End. Three-term incumbent David Marshall has not yet said whether he will seek re-election and could not be reached for comment.

However, Mako Bates, the Portland Green-Independent Committee secretary, has also taken out papers for the District 2 seat, which might indicate Marshall, who is also a Green, will not seek re-election. Marshall was a mayoral candidate in 2011 and placed fourth.

Bates is the primary author of the committee’s proposed referendum to establish a $15 an hour minimum wage in the city, which will likely appear on the November ballot.

Eastern Promenade resident Brandon Mazer, a 29-year-old attorney who is the general counsel for Shipyard Brewing Co., has taken out nomination papers for the District 1 seat, representing the East End. That seat is currently held by three-term Councilor Kevin Donoghue, who has not said whether he will seek re-election and did not respond to a request for comment.

Matthew Coffey, whose address is listed as the Preble Street Resource Center, has taken out papers for an at-large council seat held by longtime Councilor Nicholas Mavodones, who has not yet announced his intentions.

On the school board, only Holly Seeliger and Sarah Thompson – both incumbents – have taken out nomination papers for the District 2 and an at-large seat, respectively.

Residents seeking district seats on the council and School Board must collect at least 75 valid signatures from registered Portland voters to appear on the ballot. The threshold for mayor and at-large seats is at least 300.

Nomination papers, which became available Tuesday, must be returned to City Hall between Aug. 11 and 25.