Virginia's Democrat-dominated General Assembly, claiming blatant partisanship by Republican Gov. John N. Dalton, today rejected proposed changes in its congressional redistricting plan that would have aided Northern Virginia Republican Rep. Stanford Parris.

Democratic legislators portrayed the action -- a 26-to-12 defeat in the Senate for the Dalton-backed amendment -- as a major setback for the governor. Dalton had earlier charged the legislature was trying to use the plan to boost the political fortunes of former Democratic Rep. Herbert E. Harris, who lost to Parris last fall.

"We have met the enemy and he is ours," said House Majority Leader Thomas Moss.

Dalton spokesman Charles J. Davis later defended the governor's actions and sought to downplay the Senate rebuff. "I don't think this was any kind of defeat at all," Davis said.

Today's vote leaves intact an Assembly-approved plan redraw congressional election districts that most legislators believe will satisfy constitutional requirements for equal representation. The fate of a House redistricting plan, which faces several court challenges on constitutional ground, is less certain.

The Senate vote was the second political defeat for Dalton in three days. The governor was among party leaders who were embarrassed and angered last weekend when state Sen. Nathan Miller upset a Dalton-backed candidate to win the Republican nomination for lieutenant governor at the party's nominating convention in Virginia Beach.

"Dalton just doesn't seem as formidable as he did three days ago," said Del. Mary Marshall (D-Arlington). " You can hear it when people say his name."

But legislative Republicans were quick to point out that the final congressional redistricting plan clearly fails to loosen the GOP's stranglehold on the state's 10-member U.S. House delagation.

"The GOP got 95 percent of what they wanted here," said Del. Vincent F. Callahan (R-Fairfax). "If we get too greedy, we're going to end up on our rear end."

Many Republicans characterized Dalton's decision not to wrangle over the Northern Virginia congressional districts as pragmatic politics.A veto of the entire plan could well have plunged the legislature into a repeat of its months-long redistricting struggle, they said.

The approved plan drops predominantly Republican western Prince William County, the cities of Manassas and Manassas Park and a portion of Spotsylvania County from Parris' 8th District and adds them to Republican Rep. Kenneth Robinson's 7th District. it also extends the 8th farther south in Stafford County.

The result, according to Democrats, is an 8th District that Parris would have lost by 3,000 to 4,000 votes last fall, instead of winning a slender, 1,094-vote victory over Harris.

After meeting in private with Parris last month, Dalton proposed that all of Stafford County be put into the 7th District and the cities of Manassas, Manassas Park and the Parkside precinct of Prince William County be kept in the 8th District.

"There is no question they tried to draw the lines to pick up precincts" in which Harris fared better than Parris, Dalton said after the meeting.

Following today's Senate defeat, Dalton held a string of closed meetings with Senate and House Republicans and then abandoned the Northern Virginia proposal. Two other amendments to redress minor population imbalances elsewhere in the state were resubmitted, the signal that Dalton did not intend to veto the entire plan. The final plan passed the Senate 36 to 2, and won House approval by a vote of 77 to 19.

Parris characterized the action by Senate Democrats as "politics as usual," adding that he believes the approved plan will not have an adverse effect on his chances for reelection. "I'll represent whatever folks are left to me," Parris said.

But several Republican legislators, who met with Dalton late this afternoon for an explanation of his actions, said they were concerned. "It's a question of whose ox is getting gored and my congressman's ox is getting gored," said Del. Warren E. Barry (R-Fairfax). "The governor is sacrificing one particular congressman for the welfare of the others. He promised Stan Parris a very nice burial."