AUGUSTA, Maine — Maine’s former House Speaker, the executive director of the ACLU of Maine and a lawmaker from Portland are the latest to enter the race for Maine’s 1st District seat in the U.S. House of Representatives.

Former state House Speaker Hannah Pingree, 35, of North Haven, confirmed Sunday that she spent the weekend gathering signatures for her petition.

Pingree, a Democrat, said she began gathering signatures in case her mother, U.S. Rep. Chellie Pingree runs for the U.S. Senate seat held by Republican Olympia Snowe. Chellie Pingree is collecting signatures for that race.

Snowe recently announced she would not seek re-election due to the political climate in Washington.

Hannah Pingree’s state house term was limited in 2010. She is now running an inn, working as a consultant for the national coalition Safer Chemicals Healthy Families, and is raising her young daughter.

Shenna Bellows, 36, a Democrat from Manchester, this weekend also began collecting signatures for the 1st District race. Bellows took an unpaid leave from her post at the ACLU of Maine on Saturday, when she began gathering signatures.

“I’m a Mainer. I grew up in Hancock. I spent my entire career working on issues of civil rights and justice. I know I’m one of many candidates who are collecting signatures in the first congressional district,” she said Sunday. “I really don’t know yet. I’m collecting signatures to see if it’s feasible to move forward.”

Also gathering signatures for Maine’s 1st District House seat over the weekend was state Rep. Diane Russell, D-Portland.

“I’m considering running for congressional district one — if Chellie runs for senate and her daughter Hannah [Pingree] decides not to run for it,” Russell said Sunday.

The three join an already crowded field in the 1st District race.

Six Democrats had previously secured petitions: Barry Hobbins, the state Senate minority leader; Sen. Phil Bartlett of Gorham; Rep. Jon Hinck of Portland; David Lemoine, former state treasurer; Wellington Lyons; and David Costa. Hinck had been a Senate candidate, but switched Friday to the House.

On the Republican side, Patrick Calder was the first to declare he is running. However, since Snowe’s decision and since Chellie Pingree has expressed strong interest in the Senate seat, three Republicans have begun the signature-gathering process: Jonathan Courtney, the Senate majority leader; Markham Gartley; and John Vedral.

House candidates enrolled in a political party have until March 15 to collect at least 1,000 signatures for submission to Maine’s secretary of state to be eligible to run.