Proposals for both state legislative redistricting and congressional redistricting are expected to be addressed in Harrisburg today.

At the state level, the five-member Legislative Reapportionment Commission is expected to vote on final redistricting plans for the 50 seats in the state Senate and 203 in the House. The commission included the four caucus leaders, including state Sen. Majority Leader Dominic Pileggi, R-9, of Chester. It was headed by retired state Superior Court Judge Stephen McEwen, a Republican former Delaware County district attorney.

The commission adopted the preliminary state legislative redistricting plan in a 3-2 vote on Oct. 31. This is the fifth time since 1970 the state has used a commission to redraw district boundaries.

State Democrats have voiced outrage over the preliminary plan and have argued that it was done to protect Republicans. Republicans, however, have maintained that the plan was driven solely by shifts in population.

In Delco, residents and officials from Haverford, Swarthmore and Upper Darby have voiced concerns over plans to change the state House boundaries.

Pileggi released a revised Senate plan last week. The new Senate plan discarded an earlier proposal for a central Pennsylvania district that critics widely derided as a blatant example of gerrymandering.

Pileggi said his proposals modify half of the 50 Senate districts from what was proposed in the GOP-crafted preliminary plan that was the focus of two days of public hearings in November.

Lisa Scullin, a spokeswoman for the Senate Democrats, cited the overhaul of state Sen. Jeffrey Piccola’s district as one of several “definite improvements” over the preliminary plan.

But Scullin said the proposed map is designed to protect the GOP majority during the next decade of elections.

just as strongly as the preliminary proposal. She said the Democrats had not decided whether to propose their own changes.

In the state House, Majority Leader Mike Turzai, R-Allegheny, and Minority Leader Frank Dermody, D-Allegheny, were said to be working on a possible compromise map.

Two local Democratic members of the state House – state Rep. Margo Davidson, D-164, of Upper Darby, and state Rep. Greg Vitali, D-166, of Haverford – raised concerns over the preliminary plan.

Davidson did not return calls seeking comment Friday. She previously said that the preliminary plan would split Upper Darby, and several other Delco communities, “purely to benefit Republicans.”

Vitali said Friday that he believes his district, which has historically included all of Haverford, would still be divided in the final plan. Under the preliminary plan, his district lost Haverford’s heavily Republican 1st and 9th wards. He did, however, pick up Lower Merion in neighboring Montgomery County.

Vitali has repeatedly argued that this process was driven by Delco Republicans in an effort to protect the seat of state Rep. Nick Micozzie, R-163, of Upper Darby.

“Mr. Vitali should know better,” argued Steve Miskin, a spokesman for Turzai. “He keeps trying to rail on a specific House member. He knows that’s not how it works.”

In addition to the vote on the state legislative redistricting plans, congressional redistricting maps are expected to be unveiled in Harrisburg Monday. This tract of redistricting will be handled through legislation and will reduce the state’s number of congressional seats from 19 to 18.

Pennsylvania Democratic Party Chairman Jim Burn blasted the congressional redistricting process Friday, calling it a “secretive, partisan” process.

The Associated Press contributed to this article.