State lawmakers today plan to advance a proposal redrawing the state’s Congressional districts, pulling Quincy into U.S. Rep. Stephen Lynch’s district, and handing over more of Dorchester to U.S. Rep. Michael Capuano. The state House and Senate expect to vote on the proposal next Tuesday.

The proposal potentially set up a fight next year between Lynch, a South Boston Democrat, and U.S. Rep. William Keating, a Quincy Democrat. But Keating has said he will be moving to the newly formed district, which includes Cape Cod and his summer home in Bourne.

Under the proposal, Lynch loses Needham and picks up the North End, Weymouth, Hingham, Cohasset, Scituate, and Hull. His district would take on a U-shape, bending around the district currently occupied by U.S. Rep. Michael Capuano, a Somerville Democrat and former mayor.

Lynch had asked state lawmakers to keep his Congressional district largely intact, and cited its large Irish population as one reason. Asked after a hearing earlier this year about the possibility of Quincy getting drawn into his district, Lynch said many Irish Americans had migrated south from Boston to Quincy. “I’ve heard varying proposals out there and I don’t know how that’s going to work out,” Lynch said. “I really don’t. There are some natural – that whole area going from Boston down to the South Shore has been a natural migration pattern, if you will. Most of my family is already down there.”

The plan also strengthens Capuano’s majority-minority district, restructuring it to include an increase in minority voters and residents.

Because of the Bay State picking up population at a slower pace than other parts of the country, the Legislature’s redistricting committee was tasked with redrawing political boundaries for state House, Senate, and Congressional districts. That meant going to nine Congressional seats from ten.

Avi Green, co-director of the voter rights group MassVOTE, said his group would be submitting a letter but it had not taken a position. But he said they were “very pleased” with the redistricting committee’s push for a greater number of people of color in the strengthened majority-minority district, proposed to grow to 56.6 percent, from 52 percent.

The new district, as currently designed, has four major interest groups, he said: the African-American population, the largest voting bloc in the district, running southbound from the South End to Randolph; Latinos in Everett, Chelsea, East Boston, and parts of Roxbury and Mission Hill; white working and middle class voters who lean left, living in Somerville, Everett, East Boston, and in Brighton; and white liberal voters in Back Bay, Beacon Hill, and Somerville.

“It’s hard to create a more diverse district than this one without resorting to racial gerrymandering,” Green said.

“This is the strongest majority-minority district we’ve ever had in the Commonwealth,” Moran told the State House News Service. The voting-age minority population in the newly drawn district will increase from 48 percent to 51.8 percent, he added.

Lynch and Capuano will continue to share Dorchester, although Capuano’s district lines will move eastward.

State Sen. Sonia Chang-Diaz, a Jamaica Plain Democrat who represents some parts of Dorchester, said Tuesday that she was withholding some judgment until the public comment period ended on Thursday. “People are still just starting to realize the map is out,” she said. But she noted that there was some unhappiness in Jamaica Plain, since the neighborhood is getting split between the districts of Capuano and Lynch.

House Republicans said they felt “largely excluded” from the deliberations over the new Congressional maps. “While we continue to digest the numbers and totality of the maps presented to us for the first time today, we look forward to the public comment phase of this process – however brief it may be – and remain hopeful that an inclusive conversation amongst legislators will take place before the maps become finalized,” House Minority Leader Brad Jones said in a statement.

Material from State House News Service was used in this report.