The imminent resignation of Rep. Marty Meehan (D-Mass.) has one powerful women’s group plotting to send the first woman to Capitol Hill from Massachusetts in 25 years.

“We’re really excited about finally being able to elect a Democratic woman to Congress from Massachusetts,” said Ramona Oliver, spokeswoman for EMILY’s List. “There are a number of women we have been talking to” about running in a special election to replace him.

Meehan on Tuesday announced that he will leave the House after almost 15 years on July 1 to become the chancellor of his alma mater, the University of Massachusetts at Lowell.

The school’s board of trustees must sign off on Meehan’s appointment, which it is expected to do this morning.

Meehan’s departure is sure to set off a scramble, especially among Democrats who are eager to replace him. Republicans also may attempt to contest for the seat, though the district is reliably Democratic.

Meehan’s announcement ends several months of speculation that he might not finish his eighth term. Meehan sought to tamp down the rumors, telling Roll Call on Jan. 29: “I think they’re people in my district who think I’d be good for a lot of jobs, and they want my job so they throw my name out there for everything under the sun. The only problem is I have no interest.”

Just days later The Boston Globe revealed that the Lowell native was up for the university post, which has been vacant since last July.

The last woman to represent the Bay State in Congress was former Rep. Margaret Heckler (R), who spent 16 years on Capitol Hill before losing a Member-versus-Member matchup in 1982 with now-Rep. Barney Frank (D).

Women who are most often mentioned as potential candidates are Niki Tsongas, wife of the late Sen. Paul Tsongas (D-Mass.), and Eileen Donoghue, Lowell’s former mayor and current city councilor.

Tsongas said she would defer all comment on the race until Meehan’s appointment is formally announced today. But she has taken a leave of absence from her position as an administrator at Middlesex Community College to explore a run and said she has spoken with EMILY’s List officials about the race.

“As part of the process of assessing the viability of my candidacy I have talked to a lot of people,” she said.

One veteran Massachusetts political operative who works on Capitol Hill said Tsongas starts out ahead of the crowded field given how well known she is.

“If anybody had to pick the frontrunner, it would have to be her,” the source said.

A special election must be held within 160 days of Meehan’s retirement.

Whoever wins that race — and a Democrat is heavily favored — must stand for re-election in the regular 2008 election.

“The decision to leave the House has been the most difficult professional decision of my life,” Meehan said in a news release. “Being a Member of Congress has been the best job I have ever had. But after serious personal reflection … the opportunity to serve as chancellor of my alma mater is the right path for me.”

During his time on Capitol Hill, Meehan has been most associated with the issues of campaign finance reform, civil rights and tobacco control.

Scads of Bay State pols are eager to assume the 5th district seat Meehan has held since 1992.

State Rep. Barry Finegold (D) made his ambitions known before the selection committee even confirmed that Meehan was a candidate for the job.

Other Democrats lining up besides Tsongas and Donoghue: state Reps. James Eldridge and James Miceli; Middlesex Sheriff James DiPaola; Democratic National Committeeman David O’Brien; and Steve Kerrigan, a former aide to Sen. Edward Kennedy (D-Mass.).

Republicans also are eager for a shot at the Lowell-based district that Sen. John Kerry (D) and former Vice President Al Gore each won with 57 percent of the vote in the last two White House elections.

In the mix on the GOP side are Lawrence Mayor Mike Sullivan, former state Rep. Donna Cuomo, and Chuck McCarthy, whom Meehan beat 60 percent to 34 percent in 2002.

“We’re excited to compete for this potential open seat in the 5th Congressional district,” said Brian Dodge, spokesman for the Massachusetts Republican Party. “This is a strong opportunity for Republicans in Massachusetts.”

Democrats are confident they will hold the seat.

“Congressman Meehan has been a valuable and important member of the Democratic Caucus who has served the people of his district with honor and dignity,” said Democratic Congressional Campaign Committee spokesman Doug Thornell. “The Democrat to succeed him will have big shoes to fill.”

Democrats expect the winner of their primary to win the special election.

Meehan spokesman Bryan DeAngelis said Meehan “isn’t likely to get involved in the primary.”

All 12 members of the Bay State’s Congressional delegation are white Democratic men, most of whom have put in many years on Capitol Hill.

In 2004, many of the state’s 10 House Members, including Meehan, began bolstering their war chests and raising their profiles in the hopes that Kerry would become president — or leave his seat to run for the White House again in 2008.

Meehan stockpiled $5.1 million in campaign cash since 2004 in hopes of competing for an open-seat Senate race that never materialized.

The DCCC would like to get its hands on Meehan’s cash. DCCC officials intend to broach the subject with him very soon, according to one knowledgeable source.

DeAngelis said Meehan is “going to check with the Federal Election Commission on what his options are” for the money.