For a decade, developer Charles Fairchild has pressed his controversial plans to build Potomac Center, a proposed high-rise office complex on the George Washington Parkway that foes have dubbed "Crystal City II."

A 1978 lawsuit by citizens opposed to the project was dismissed by a federal judge as "not yet ripe for review" and in April, Fairchild finally won preliminary approval from the National Park Service for a crucial parkway interchange south of National Airport.

This slow but steady march toward groundbreaking prompted opponents of the complex to announce yesterday the formation of a coalition to fight "unplanned, uncoordinated and irresponsible development" at the site, said group spokesman Phil Sparks.

The coalition, called the Daingerfield Island Voter Education Organization after the park service-operated marina opposite the proposed building site, "has serious doubts about the size and scope of the proposed development . . . It could create an impossible bottleneck of traffic along the parkway," Sparks said.

A key test is expected tonight when the Alexandria City Council is scheduled to consider approval of zoning for the center, which the coalition contends would permit construction with double the density recommended by one recent $33,000 city study.

Fairchild's plans call for a 1,300-room hotel, 835 condominiums, extensive office and commercial space and -- most alarming to his critics -- parking for an estimated 11,500 cars, which the coalition says will hopelessly clog the already crowded parkway.

Sparks said yesterday the group will seek council approval for lower building heights (scaled down from 150 feet, or 15 stories, to 77 feet), and assurances of a Metro station paid for by Fairchild. The group also is considering legal action against the park service to block the proposed parkway interchange, Sparks said.

Fairchild could not be reached for comment.

In 1970, the National Park Service traded access rights to George Washington Parkway in exchange for 29 acres of wildlife land owned by Fairchild in Dyke Marsh, south of Alexandria. Fairchild had wanted to build high rises with a Palm Beach-type waterfront there, but was blocked by Fairfax County.