TALLAHASSEE — The Senate Reapportionment Committee on Monday approved a plan that changes lines for congressional districts in Southwest and Central Florida, setting up a potential collision with the House.

Even as members of the House rejected an amendment to a "base map" developed by legislative staff members ahead of the session, the Senate panel approved on a voice vote new boundaries proposed by Sen. Tom Lee, a Brandon Republican and former Senate president.

Lawmakers returned to Tallahassee last week following a July ruling by the Florida Supreme Court striking down eight of the state's 27 congressional districts for violating the anti-gerrymandering "Fair Districts" standards approved by voters in 2010.

It is the first of two redistricting sessions scheduled to be held this year. Another is needed to redraw Senate lines after a lawsuit dealing with those districts was settled after the Supreme Court decision on the congressional plan.

The proposed map approved Monday by the Senate committee addresses two concerns raised by lawmakers in the Tampa Bay area and Southwest Florida.

First, it would consolidate eastern Hillsborough County into one congressional district shared with the northwest corner of Polk County. And second, it would put all of Sarasota County into the same district, one that also includes western Manatee County and the far southwestern corner of Hillsborough.

Lee and legislative staff members said the proposal would only slightly change one of the three measures used to determine how compact districts are and would have two fewer city splits when compared to the base map. But the ripple effects of the proposal would also cascade through Central Florida and recast the one district that would have been completely contained in Orange County.

"That kind of gives me a moment of pause that a huge county like Orange County now has no congressional seat that's wholly incorporated in it," said Sen. Oscar Braynon, D-Miami Gardens.

Other efforts to amend the map largely focused on Congressional District 5, represented by Democratic Congresswoman Corrine Brown. The Supreme Court ordered lawmakers to reorient the district, which currently ambles from Jacksonville to Orlando, so that it runs east-west along the top of the state. Brown has fiercely fought the changes to her district, and some local leaders have joined her calls to salvage the north-south configuration.

"If we strategically, intentional or not, impact District 5 in such a way that the minority community cannot have their candidate of choice we will continue to go down this road ... of unrest," Jacksonville City Councilman Reginald Brown told the committee.

But, after discussion, senators withdrew proposed amendments that would have pushed the district at least somewhat southward and pushed more of Leon County out of Brown's territory.

Sen. David Simmons, an Altamonte Springs Republican who helped craft one of the amendments, warned later in the meeting that the changes in either the congressional map or the Senate map could harm efforts to make sure African-American and other minority voters can elect candidates of their choice.

"I'm really afraid that the rich diversity and the culture that is reflected in our Senate and in our Legislature and now in our Congress will be diminished," Simmons said.

The Senate committee approved the changes as the full House moved forward with the base map and prepared for a vote Tuesday. During a floor session, the House rejected a proposed amendment to put all of Sarasota County in the same district.

The House and Senate seemed unconcerned about whether they could reconcile their differences before the scheduled conclusion of the special session on Friday. They all but ruled out forming a joint House-Senate conference committee to hammer out a compromise, but Senate Reapportionment Chairman Bill Galvano assured reporters that any negotiations between himself and House Redistricting Chairman Jose Oliva, R-Miami Lakes, will take place in public.

"I don't anticipate that there will be any phone conversations," said Galvano, R-Bradenton. "If we're going to have a conversation about the differences between the maps, we're going to do it open and in the public."

House Speaker Steve Crisafulli, R-Merritt Island, said he hadn't seen Lee's plan.

"The House is focused on the job before it, and at this time we're focused on moving a product off this floor and sending it to the Senate, and then we'll see what comes from the Senate," he said.

Oliva also said he hadn't looked at Lee's map, but projected calm.

"It's only Monday," he said. "I think we'll be fine. We have until Friday."

Meanwhile, the political fallout from the maps continued. Former Orlando Police Chief Val Demings, who narrowly lost to Republican Congressman Dan Webster in 2012, said she would make another bid for the Congressional District 10 seat, which would favor a Democrat under either plan currently in play.

"Just as I took on crime in Orlando by straight talk and bringing people together, I will work to move our state and country forward in Congress," Demings said in a statement issued Monday.